5. The Last Major Ice Age

by Eric Grimsrud

In my first Post called “1. A Common Sense View of AGW”, I presented a simple qualitative view of the AGW problem in order to relate the essence of what the debate is primarily about. In this Post 6, we will move on to consider some basic quantitative aspects of AGW. In this section, we will be searching, in particular, for good expressions for what’s called the temperature “Sensitivity” for CO2. That number indicates the increase in average global temperature that would be caused by a doubling of its concentration. To better appreciate the immediate importance of this number, recall this. Atmospheric CO2 was at 280 prior to the Industrial Revolution. It is now 392 and rising at a rate of 2 ppm per year. Therefore, a “business as usual” course will lead to a doubling CO2 within the current century (by about 2094).

If the quantitative expression for CO2’s sensitivity is only say about 0.2 degree C, as is claimed, for example, by H. Leighton Steward in his book Fire, Ice, and Paradise, page 23, then we could indeed conclude that AGW does not pose a problem of such great immediate concern. If CO2 sensitivity is much higher, however, then we have to be very concerned about this issue and that level of concern should be in proportion to the actual value of CO2’s Sensitivity.

So what is the best way to determine or at least get a good estimate of the Sensitivity of CO2. This is being done by model calculations using huge computers to “simulate” the entire Earth. I will not be using the results of those studies here, however, because there is a much more reliable way to determine Sensitivity and that is by looking at the historical record. Even the computer modelers acknowledge this and, in fact, use that historical record to test their models. After all, the real world acts in accordance with the effects of all of the relevant variables – whether we are aware of all of them or not. So I will be taking the advice here of one of America’s most popular philosophers, a man named Yogi Berra, who is reported to have said “predictions are hard to make, especially about the future!” and “a person can observe a lot just by watching!” So let’s now do some “watching”.

In this post, we will be focusing on the “Last Major Ice Age” in which we all presently live and which began about 35 million years ago. While I understand that there have been about four previous Major Ice Ages hundreds of millions of years previously, we know much more, of course about the most recent one and have a great deal of information concerning it, as we will see.

First, let me introduce you to a single reference that I will be making extensive use of here. This reference is a paper entitled “Target Atmospheric CO2” by Hansen et al. published in The Open Atmospheric Science Journal, in 2008, volume 2, pages 217-231. This journal is available to the public and this article can be retrieved from the internet at http://www.bentham.org/open/toascj/openaccess2.htm. Use of this reference is also appropriate here because it summarizes great deal of relevant literature while providing new information and insights. In addition, a separate and even more extensive article entitled “Supplemental Material” is provided with it. In my many years of teaching, I have found it to be essential for the students to have materials from which they themselves can read and interpret the data and figures I use in the classroom. My use of this reference here will serve that purpose. At the same time, of course, all of the literature is important and will be referred to as needed. Careful considerations of this one paper, however will get us quite a ways down the road initially.

First, in order to see where the Last Major Ice Age occurred in time, please have a look at Figure 1 (all figures, unless indicated otherwise, come from the reference cited about).

Figure 1. This graph shows the temperature of the Deep Ocean over the last 65 Million years before present (My BP). (These determinations were made by the isotopic analysis of the oxygen atoms found in the CaCO3 remains of foraminifera shells found in ocean bottom core samples. Please see Hansen et al. for the details of this widely used procedure). The period of the Late Major Ice Age in indicated by the blue line beginning at about 35 My BP. Note that temperatures are shown a variations relative to the present time.

We will come back to and use this figure in future discussions, but for now will use it to gain some temporal perspective on the Last Major Ice Age. First, note the temperature rise that occurred right after the extinction of the dinosaurs, about 65 My ago. This initial rise before 50 My BP is thought to have been caused by the continental shifts at the Asia-India interface and associated volcano activity causing CO2 to increase to approximate 1500 ppm. After 50 My BP a slow and steady temperature decrease began. Until 35 My ago the world was ice free with a sea level of about 70 meters above the present level in 35 My BP and about 200 meters in 50 My BP (due to thermal expansion at high temperatures).

The blue line starting at 35 My PB, indicates temperatures after ice began to build up on our planet, first on Antarctica and then on Greenland and then of the other continents. The world had thereby entered the Last Major Ice Age. At the very right side of the graph temperature is shown over the last few (2 or 3) million years during which ice formation was often extensive over most of the continents, including North America. Note how temperature rose and fell quite remarkably over this most recent period. This latter period includes the cold Glacial and warmer Interglacial Periods of the Last Major Ice Age. Often these glacial periods are referred to as “ice ages” in the literature. In order to avoid the confusion that thereby results, I will refer to them as “glacial periods.”

Now let’s move on the Figure 2 shown below.

Figure 2. These data were obtained from the Ice Core Records, which I’ll assume for the moment that you have heard about. By examination of these ice core samples, it is possible to determine many things including the temperature of Antarctica (and Greenland) over the last 800,000 years and the historic background concentrations of various minor components of the atmosphere. The measurements shown here of temperature and the greenhouse gases, CO2 and CH4, over time serve to illustrate an important point – their high level of reproducibility. Shown here are many measurements made by different scientific groups at different times at different locations in the Antarctic. Similar measurements from Greenland’s ice cores (not shown here) are also in close agreement The ice core records are clearly trying to tell us something about the most recent period of the Last Major Ice Age.

Now let’s move on to Figure 3 where the same sort of data are shown along with some analysis of that data.

Figure 3. (a) Measurement of two major GHG’s and also Sea Level are shown. Sea Levels can be derives by several means (see Hansen et al.) (b) Climate Forcing value have been calculated here from the GHG data and sea level data (Hansen et al. provide a good explanation to the term, Climate Forcing, at the beginning of their article). (c) From the expected Climate Forcing values, expected average global temperatures have been calculated and then compared to measured temperatures. In this case, an estimate of the average global temperature variations have been obtained by dividing the measured Antarctic temperature variations by 2. This is because temperature variations on the Antarctic are typically about twice the observed changes in average global temperature. Note that the fit between the calculated and observed temperature variations thereby obtained is very good.

[A short time out: The term, albedo, means the fraction of incoming solar radiation that is reflected back into space. The present albedo of Earth is about 0.30. During a glacial period, it is about twice that, or about 0.6 0.32 [Edit on 1/4/11]. The temperature of the Earth is primarily determined by three factors. These are sun’s intensity, the greenhouse effect and the Earth’s albedo. All of the many other detailed factors we will be discussing affect temperature by their effect on either the greenhouse effect or the albedo].

Now the reason why the general agreement between the calculated and observed temperatures shown in Figure 3c is so significant here is that this level of agreement can only be obtained using values for CO2 Sensitivity that are very much greater than the negligible level of about 0.2 degree C mentioned at the beginning of this post. The results described here could be explained only with use of a CO2 Sensitivity of about 3 degrees C for “fast feedback” processes and about 6 degrees C if slower surface albedo feedbacks were also included.

Let me explain the fast and slow feedbacks a bit more. As the temperature rises due to any “Forcing Agent” that causes a change relative to the normal, other changes also quickly occur – including increased water vapor and changes in cloud formations. All of these fast changes contribute to the CO2 sensitivity expected in the short term of a few years or a few decades. These changes can also cause slower changes in the albedo of the Earth, however, by causing the melting of sea ice or changes on land such as the conversion of barren snow covered regions to vegetated regions. While all of these factors are complicated and might be beyond our present ability to describe them well in computer simulations, Mother Nature is revealing the magnitudes of their net effects via the ice core samples.

So it appears that Mother Nature is telling us that the Sensitivity of CO2 is somewhere between 3 and 6 degrees C depending on the time span you wish to use. Figure 3b suggests that the Forcing caused by the GHG effects and the albedo effects are approximately equal. The GHG effect acts faster, but with more time, the albedo effect adds to the initial GHG effect thereby doubling the net sensitivity of the GHG’s.

All of this is can be additionally explained by bringing in Milancovitch’s calculations of the Earth’s subtle motions relative to the Sun’s position which became important during the recent glacial and interglacial periods of the Last Ice Age. A summary of this is as follows. As the Earth goes through its subtle variations of distance, tilt and precession as it revolves about the Sun, slight changes in the solar intensity in the both hemispheres occur. What happens in the Northern Hemisphere is most important because of its greater land masses. If the Northern Hemisphere happens to have a worse than average summer, the ice on it tends to grow. If it has a better than average summer, the ice on it tend to retreat. These changes in ice area cause large changes in the Earth’s albedo. In this case, we call this change a “positive feedback” because the albedo change reinforces the initial direction of change. Only after the information of the ice cores started to be revealed in the 1990’s did we realize the calculations of Milancovitch back in the 1920’s where of great importance. Until then, Milancovitch’s Theory was just one of many that awaited testing by measurements.

So the slight motions described above are now thought to initiate a change in global temperature. Then, as expected, both the albedo of the Earth and GHG’s will follow in their expected ways. For example, if that initial orbital change causes some harming, ice will retreat and the albedo will decease – causing more heating by the Sun. At the same time, more GHG’s will be emitted by the oceans as they warm up – causing more increased temperature due to their GHG effect. A lag between the initial increasing temperature and changes in both albedo and GHG concentration is expected. These secondary changes, however, will greatly contribute to the subsequent net warming (the initial forcing of the orbital change is small relative to those of the albedo and GHG changes). For the case of CO2, the ice cores indicate that its delay of change is typically about 800 years, which is small relative to several millennia of accelerated warming that then follows.

Let’s now consider Figure 4.

Figure 4. Most of this graph should now look somewhat familiar to you. Most of it shows the record (over 800 years this time) of temperature measurements via ice core data along with just the Forcings of the GHG changes this time. The GHG forcings have been arbitrarily scaled (for convenience sake) so that they are more easily compared to the observed changes in temperature. In the very right portion of this graph, however, modern changes GHG Forcing is shown on an expanded time scale along with the global temperature (purple line – ignore the black line for now, as we will discuss it extensively in my next post concerning “the Age of Man”)

So what’s to be learned from Figure 4? First, notice how temperature has closely tracked Forcing by the GHG’s for the last 800,000 years. Yes, changes in the GHG’s follow initial temperature change, but temperature also followed subsequent changes in the GHG’s.

Now look at where we are today. During the last century changes in GHG Forcing has gotten ahead of changes in temperature. (Note also that that has never happened before during the 800,000 year record of the ice cores). This lag is due to the heat inertia of the planet (mainly its oceans) and is evident in Figure 4 only because we have used a less coarse time scale for the modern data. At the same time, we know from the long term record shown on the left that temperature will catch ups with GHG Forcing.

If we want to avoid that temperature increase in the upcoming decades the question then is can we bring the GHG Forcing down relatively quickly before temperature catches up. In addition, do we really want to increase the present GHG Forcing with “business as usual” practices? We will hopefully have that discussion soon, if we agree that there is problem here that needs to be addressed.

Looking ahead a bit, some will say that GHG’s forcing is going to come down naturally – possibly by CO2’s transport into the oceans. While the existing literature on that point will offer little hope along those lines, we will consider it and other related aspects in future posts.

The most important point I have tried to make here in this Post 6 is that the Sensitivity of CO2 is somewhere between about 3 and 6 degrees C depending on whether we are talking about a short term (say several decades) or a longer term (say several centuries) period. This deduction has come from direct measurements of the past via the ice core samples. Therefore, it appears that Mother Nature is telling us that CO2 sensitivity is likely to be about 15 to 30 times greater than more comforting, estimate of about 0.2 degrees C offered by Mr. Steward (as described above) via his greatly oversimplified and purely theoretical arguments (they can be seen on the internet at http://www.montanapetroleum.org/assets/PDF/articlesReports/2010-Treasure-State-Journal.pdf).

A General Discussion of the Ancient Atmosphere as Revealed by Figure 1.

In an effort to keep this as brief as possible, I will make just a few comments below that I think will be relevant to future discussions of AGW.

[1] First, note how high T became at about 50 My ago.

A major reason for the increase during the prior 10 Mys is thought to be due to continental shifts occurring at that time. Most importantly, it is thought that the then island continent of India was then moving “rapidly” northward and was crashing into and sliding under the larger continent of Eurasia. The volcanic activity associated with that event is thought to have thrown large quantities of CO2 into the atmosphere over that 10 My period, thereby increasing CO2 levels to about 1500 ppm +/- 500 ppm. (The methods used for both CO2 and temperature are probably same as used for figures shown previously in Temperature and CO2 History. If needed, we can go into those details later).

[2] Then note that a long slow decrease in T occurred until about 35 My ago.

This decrease in T is thought to be accompanied by a decrease in CO2 so that by 35 My ago, the CO2 level is thought to have decrease to about 450 +/- 100 ppm. If that approximately 1000 ppm decrease occurred smoothly over the time span between 50 and 35 My ago, the rate of that change would have been only about 0.0001 ppm per year. This is even slower than the maximum rate of CO2 change observed over the 800,000 year record of the ice cores (about 0.01 ppm) and, of course, is many orders of magnitude smaller than the present rate of change (about 2 ppm).

The major cause of this slow removal of CO2 after 50 My ago is thought to be “weathering” by which the CO2 in raindrops and in the oceans reacts with inorganic matter (rocks) and is slowly converted to solid matter such as limestone, CaCO3. The freshly exposed granite of the Himalayan Mountains (formed by India’s undermining of Asia) is thought to have facilitated this weathering process.

[3] Although both the CO2 and T data is not as accurate as that obtained from the ice cores, we can nevertheless deduce a rough estimate of CO2 Sensitivity from it.

A decrease from 1500 ppm CO to about 450 ppm CO2 between 50 and 35 My ago is equivalent to about 1.7 “halving” (in order words, the reverse would be about 1.7 doublings). Over that period T appears to have changed from about 13 to 5 degrees C relative to the reference T of today – a total change of about 8 degrees C. The temperature being shown here for the Ocean Bottom and the corresponding variations in average global T might be high or lower. Hansen et al. assigned this uncertainty of conversion to be about +/- 50%. Going with the 8 degree value (no conversion factor used), we come up with very rough estimate for CO2 sensitivity of about 5 degrees C with a conservative estimate of the net uncertainly of about +/- 3 degrees C.

Next it is informative to consider what type of CO2 Sensitivity this is. Is it closer the the fastback or slow feedback types discussed previously in our analysis of the ice core data? The answer is clear. During the period between 50 and 35 My ago, the Earth was a “water world” – there was no sheet ice on the planet – as there was increasingly after 35 My ago. Therefore the Sensitivity term we just estimated is of the fast feedback type for which the feedbacks of water vapor and clouds are dominant. There was no ice and its effect on albedo that needs to be consider over this period.

Now note that that the ice core data suggested that the magnitude for the fast feedback sensitivity of CO2 was about 3 degrees C, Thereby being in agreement with the rougher estimate of the same parameter just deduced from T and CO2 changes occurring between 50 and 35 My ago.

[4] The Paleocene-Eocene Thermal Maximum (RETM).

Note the slight peak in T seen in the year 54 My ago. This is called the RETM and is thought to have been caused by a sudden huge burst of methane thrown into the atmosphere at that time. The cause of this is generally thought to be the conversion of solid “methane-hydrates” to gaseous methane which in turn was caused by the increase in ocean bottom T occurring at that time. (Note this form of methane-containing ice is what formed and then caused the pipes to block last summer in attempts to capture the oil and methane escaping from the damaged Gulf Coast well head).

When the CH4 that entered the atmosphere during the RETM, it was oxidized quickly (within a few decades ) to CO2 thereby providing us with a unique and natural “experiment” from which to learn. One thing we learned is that is appears to have taken about 150 millennia in order to remove the excess CO2 that the RETM punched into the atmosphere. This observation is in good agreement with the very long lifetimes for EXTRA CO2 that many modelers presently claim in simulations of this process.

Another point concerning the RETM becomes clear when we consider the fact that the Earth is now literally loaded with methane hydrate deposits in their coastal sea bed. If the oceans at allowed to heat up sufficiently (and we don’t know how high a T this would require) those methane hydrated deposit will release. This event would indeed constitute what is known as a “tipping point”, at least, or even a “point of no return” as generally defined to represent two different levels of distinctly “bad news”.

[5] Speaking of “tipping points”, the major point of Hansen’s et al.’s paper is to show that we have already passed one with 392 ppm CO2 in the atmosphere.

He argues that the Forcing associated with that level of CO2 is moving us in the direction of an ice free world and that level of forcing – even if not raised further increased by business-as-usual putting 2 ppm additional CO2 into the atmosphere every year – has to be reduced “quickly” before the initial effects of sheet ice changes are overcome. More specifically he argues that we have to get down to 350 ppm in order to get safely away from that tipping point. Since Hansen et al. have related all of this in detail in there paper, I will stop there.

Comments

As we, “jurors”, can see from the above presentation complied from Hansen et al work, the data are of highly speculative and imprecise character.

To start, no definition of “global temperature” was given, as was expected by many. Now we must deal with new object, “ocean deep temperature”. Again, what is that? Contrary to the pointer, the Hansen article contains no details on this “widely used procedure”, which I suspect is refereed to highly speculative procedure of conversion of oxygen isotope ratio into undefined “global temperature”.

Now, the “Last Major Ice Age”. What is that? It is a customary term in climatology that last major ice ages occurred every 100,000 years, and bout 40,000 before that. The Hansen’s article contains zero occurrences of “Major ice age”. Why do you invent new and potentially confusing terminology?

Then, you promised to use data mostly, and restrain yourself from using models. Yet your charts frequently contain “calculated temperature”, all compared to other calculated “observed temperatures” from ice cores. We all know how accurate is the isotope fractionation map into “global temperature”, and even then you mention a fudge factor of 2X when comparing these speculatively calibrated time series. I am not even asking about accuracy in timing of the events.

Again, even assuming that the isotope data were correctly converted into (still undefined) global temperatures (which is already a logical nonsense), and dissolved gases in ice samples correctly represent ancient air composition (after only year of sitting in storage and decompressing), the allegation of climate “sensitivity” of 3 to 6K/2xCO2 are unfounded. According to the Vostok data for deglaciation episodes, the relationship {CO2=>T} formally produces climate sensitivity of 18 K per 2xCO2 (if we assume the AGW concept as “CO2 is the major driver of climate”).
see:
Vostok
and
Correlation

This is surely a 8-fold discrepancy that needs a serious explanation, not hand-waiving.

To avoid repetition of arguments about “slow feedbacks” and “unknown factors” during several past deglaciations, please visit this funny discussion with few determined climatards.

What the Mother Nature may be telling us is that changes in CO2 have no measurable effect on climate, and {TCO2} relationship just appears as a side effect ocean and biosphere warming (due to yet unnamed other suspects).

I short, I am not disappointed, this is all as expected. The prosecutor’s case against CO2 is completely circumstantial.

Yes, terms can get used differently and that cause confusion. Some are careful to use the last “glacial period’, as I do, rather than the “last ice age”, as many do, when referring to the event that ended only about 15,000 years ago. Since the terms glacial and interglacial generally have only one meaning, I’ll stick to that usage here. As you point out, however, some who refer to the “last ice age” could be referring to two very different periods.

While we often prefer to talk about and compare global average temperatures, unfortunately direct measurements don’t ever come to us that way. Therefore, we also have to use names that indicate where the measurements come from. Thus, names such as “ocean bottom temperatures” or “polar region tempertures” and even “proxy temperatures” appear everywhere in the literature. If I every implied that I could remove this complexity in a prior statement, I certainly would deserve the criticism you dished out. Instead, I should have warned you, I guess, that the science and its communication can be complex.

And what’s that your are suggesting? Discussions of science without models? Do you think our science books should consist of a multitude of facts and no “stories” linking things together? That can’t or at least shouldn’t be done – unless you want your science to be incomprehensible by the human being and boring as can be. In doing research, “theory guides and experiment decides”. In this way good models that explain the result can be identified and used. Only models and not facts suggest cause and effect relationships. Let me write that again === Onlyh models and not facts suggest cause and effect relationships.

More on this point. There are no facts that will ever prove that a hypothesis is true. For example, in a couple hundred years from now, if the entire world has turnd out to be toast, that “observed fact” would not prove a cause and effect relationships such as described by the hypothesis of AGW. By then, the model of AGW will probably still be intact (in spades in fact), but it will still be just a theory. Scientist know this and you should learn the point – that we advance in science by proposing models and by continuously testing them in order to find the best one.

Therefore, you should not be so surprise by finding the word such as “models” or “ocean bottom temperatures” incorporated into discussions concerning science.

Sorry, I can’t help you with your dissappointments any more than that – but I do hope my remarks help. A far worse option for you, of course, is simply to deny the validity of science altogether – as many have done throughout history whenever they don’t like it’s message. I hope you will not become one of that crowd.

We witness a strong debate on the correlation of CO2 air concentration and earth surface temperature. However, the cause of that correlation, and the sources of the driving force(s), are at best obscure, not at all settled science. . . I note the role of sea water, and glacial polar ice as well, as a moderator or buffer. From daily experiences with carbonated beverages, the historic method of making champaign (cold winter air temperature allows uncorking of young champaign bottles to dribble out solid residue without loosing any CO2), etc, it is quite clear that it is more probable that temperature rises due to processes other than anthropological releases of CO2 from energy producing activities are instead the driving force. This includes vulcanism heat issuing from the molten planet interior (which I suspect for Venus), and solar energy variation (variation in the “Solar Constant”). winter/summer solar constant variation is indeed due to our seasonal variation of sun-distance, a well established elliptical path in our time. If one postulates that this distance can change monotonically, show me the energy and momentum sources that can affect such! I think there are none. We do have tidal energy dissipation, which acts to slow the rotation of the earth, but this is known to be just some microseconds per year. Axiomatically, if we were spiraling in toward the sun, our years would be getting shorter. In our age of “atomic clocks”, this will be easily detected if it were happening… perhaps microseconds per year? Any volunteer here to bring us up to date on those? …

Precession of the earth’s rotational axis on the sun-earth plane rotation plane: Right now, our axis points near Polaris, but that’s known to be changing at a rate that indicates a 26,000 year total period… But that only determines when our seasons occur. More significant is the migration of the earth rotational pole about the surface; that affects who gets more evenely divided nights vs days, and who gets temperate climates, who gets polar weather. In the first approximation, both these precessions affect the distribution of temperature, not the average temperature.

That leaves the champaign effect to be understood and evaluated. It is clear, to me anyway, that CO2 absorption/emission from the sea, lakes and rivers is an active process day in, day out, summer, winter. “Acid rain” is a highly suspect carrier in this process. So far I have seen only one or two verbal reports (no data) that those few such CO2 meters find variations with altitude and with latitude as well.

Therefore if CO2 concentration meters are in use (pray that some are trotted around daily – as common as thermometers) to give us a diary of how much CO2 is where to tell us where it’s going, then we should have a better understanding of its sources and its sinks.

One should expect that the warm El Ninio High should pick up CO2 from the sea, while air masses stagnated over cold seas should have a lower CO2 concentration. CO2 concentration in winter “Alberta Clippers” carrying Polar Continental air may be somewhere in between; but who knows how well cold glacier ice absorbs CO2? Likely it is just the precipitation (snow) that is the carrier… and that snow fell from air that was previously wrung clean of much moisture and CO2 via acid rain.

Finally there is the cause-and-effect issue to study: Records reviewed here recently indicate that indeed, CO2 concentration increases lag in time behind temperature increases and vice versa. That makes sense where the water bodies are acting as absorbers and emitters.. Where is the correlation function analysis that connects the two?

AND most of all where are the error bars indicating the confidence limits (marking the three band) of a hypothetical temperature rise? May we depend on honest scientists to process and report these variable values and graphs?

To demonstrate the competence of the science in promulgating CO2 behavior, I want to see data (and their error analyses) on CO2 distribution and migration issues (CO2 3D concentration and CO2 migration trails. Is there a CO2 “gulfstream”?

On the basis of as yet unreported error bands (the three sigma ranges of uncertainty), just how reliable is the inference that we are headed for “trouble”? Which of our national wealth, time, taxation and angst must be flung against this “trouble”? When? How much (if any)?

Dear Dr. Eric, I appreciate your concern about my options of being denier of science. I don’t deny science, I deny AGW climatology as being science, and your posts give me plenty of justification for this. Let’s recoup the standing:

(1) You failed to provide definition of your major term, “global average temperature”. Therefore all your subsequent constructions have little to no ground, scientifically speaking. How we can compare something we cannot define and therefore calculate or measure?

(2) You jumped right into criticism of “climate sensitivity” without giving a definition what does it mean. You alluded that the true definition is based on huge computer models that you don’t need to discuss because there is “much more reliable way by looking at the historical record”. You even expanded that “the real world acts in accordance with the effects of all of the relevant variables – whether we are aware of all of them or not.” I could not agree more on that. So, I looked at historical record, Vostok ice core data, and I found that the formal (as I understand it, dT/dC in differential form) sensitivity of global average temperature to change in CO2 is 18K per CO2 doubling. Are you saying that this is the number we should expect when CO2 increases?

(3) You also forgot to introduce the concept of “climate forcing”, especially from GH gases.

(4) You have “corrected” the temperature variations for Antarctic by 2, because of what? Why this crude fudge factor doesn’t concern you, and you declare this fudge as “pretty good fit”? Is this the typical way how climatology “works out” discrepancies in data from different sources? Do you want us to believe that fudge factors as 2X are scientific, especially when your statements are eventually concerned with 0.3% changes in “global average temperature” over the course of 100 years?

(5) Further you are saying that you can achieve this fit only if you assume climate sensitivity to CO2 as 3K to 6K. What were your assumptions about cloud cover during this period of time? As I demonstrated in comment 68@4, 1% change in cloud cover exceeds effects of CO2 variations in ice record, and there is an observational fact that cloud cover did change by many % on decadal scale, and no observations exist for longer scales. I ask again: could you provide records of %% of cloud cover during several ice ages? If not, why should we believe that CO2 is the only suspect?

(6) You said: ” So what’s to be learned from Figure 4? First, notice how temperature has closely tracked Forcing by the GHG’s for the last 800,000 years. Yes, changes in the GHG’s follow initial temperature change, but temperature also follow subsequent changes in the GHG’s.”

No, this is a loaded speculation, we cannot learn this from Fig.4. Alternative and most logical explanation of similarity in two curves is that CO2 is some simple proportional function of T, and no further and more complicated explanation is necessary.

This has become a farce. I know, I am sure a lot of people who read this blog know, and I am even more sure Dr. Ed knows, that you cannot prove CAGW using the “scientific method”. It wouid appear that Dr. Eric knows this as well. So he has abandoned the IPCC approach, knowing full well that if he tried to defend it, he would lose the argument hands down.

So Dr. Eric has proposed a non-peer reviewed, short treatise, which he claims proves that the climate sensitivity is high. I dont believe it, and I am not going to waste my time looking at it in detail.

Acid rain…. rain can contain carbon dioxide as well as the other compounds mentioned. I believe that even common rain has pH sligtly below 7, an acid indication, on the basis of the dissolved CO2, which combines with water to make carbonic acid, to wit (Wikipedia):

Citizen’s question: “In testing local creek water and rainwater, I found a rather substantial difference in pH. The rainwater was about 5.7 pH while the creek waters averaged around 7.9. What could account for these differences? What sort of conclusion might I be able to draw from this?”

Wiki Answer: ” First, the rainwater in your area sounds “normal”. Most rainwater has a pH of 5.6 to 5.8, simply due to the pressence of carbonic acid (H2CO3). The latter is formed from dissolved CO2 gas and H2O. The source of the CO2 is the atmosphere, which presently contains about 380 ppm CO2…………….”.

Another answer (unaudited): “From MemphisP – Rain water on average now in 2009 has a pH between 4.3 and 5.6….”.

Hmmmm- further south, rainwater has lower pH…. or is it urban rain water…?

Dear Dr. Eric,
I can happily withdraw my point that there was no definition of sensitivity. The definition in fact was given in independent sectionhttp://climateclash.com/definitions/ . I apologise, my bad. However, the rest of my Pragraph(2) is a precise account of your third paragraph, including precise quotation of very long sentences of yours.

Your text is:
“So what is the best way to determine or at least get a good estimate of the Sensitivity of CO2. This is being done by model calculations using huge computers to “simulate” the entire Earth. I will not be using the results of those studies here, however, because there is a much more reliable way to determine Sensitivity and that is by looking at the historical record. Even the computer modelers acknowledge this and, in fact, use that historical record to test their models. After all, the real world acts in accordance with the effects of all of the relevant variables – whether we are aware of all of them or not.”

My account of the above is:
“(2) … You alluded that the true definition is based on huge computer models that you don’t need to discuss because there is “much more reliable way by looking at the historical record”. You even expanded that “the real world acts in accordance with the effects of all of the relevant variables – whether we are aware of all of them or not.” I could not agree more on that. So, I looked at historical record, Vostok ice core data, and I found that the formal (as I understand it, dT/dC in differential form) sensitivity of global average temperature to change in CO2 is 18K per CO2 doubling. Are you saying that this is the number we should expect when CO2 increases?”

Therefore, please kindly point out which “things” did I copy incorrectly, which one I made up, and which ones are “stupid”.

Again, according to the definition you and Dr.Ed agreed upon, http://climateclash.com/definitions/, the global climate sensitivity inferred from Vostok proxies is 18K. How it is a good fit to models and modern instrumental observations?

Dear Dr. Eric, I am enjoying this debate and look forward to future posts from both you and Dr. Ed. It does seem presumptous to assume that the pre-industril CO2 level was 270PPM. I recognize that many have accepted that but others, including Nobel Laureates have done sampling over the past 180 years which show a much different picture. I refer you to the works of the late Ernst Beck and A. Jaworowski. Discard that piece of information and the rest of your post is suspect. I also point out that although you were quite enthused about the conclusions regarding Figure #3, there was a significant disconnect in my mind. Forget about the time relationships between the events which are obscured by the large span covered, forget that you must use a factor 2X what has been determined to be be the CO2 sensitivity, and forget that all this happened without the benefit of mankind. You completely ignore all of the other “forcings” that could have played upon the Earth. For example, the magnetic link between the Earth and Sun, which varies significantly even reversing in alternate solar cycles, has been shown to affect cloud cover. As mentioned above that is significant. You show no regard for the epitrochoid orbit of the Sun caused by the motion of the Jovian planets which has excellent correlation with Earth’s climate. (I know correlation is not causation but without correlation you have nothing.) The models you mention disregard the effect of the solar irradiance because of its small variation within a solar cycle but which varies significantly from cycle to cycle, not to mention the UV component which exhibits even greater variability (more than 6% in the last solar cycle) As Piers Corbyn has suggested, transpiration caused by CO2 improved vegetative growth may actually decrease temperature. Sorry if I reiterated some of the above comments but other specifics in relation to these points needed to be raised.

Dr. Eric,
I have a comment and question I would like you to respond to (more to come later).

The comment relates to the expansion of sea water. If the bulk of the oceans went from 12 C to 2 C (the full range from 65MY ago) the volume would only decrease sea level by 7 m. In fact if it went from 4 C to 2 C (the range from 35 MY ago to present), the change would be near zero. Almost all of the actual effective sea level change due to thermal effects occur in the surface layer (top 500 m). Increasing this by 1.5 C by 2100 would only cause about 1o cm increase, which is the maximum thermal expansion effect likely in the next several hundred years. Almost all of the significant increase or decrease in sea level is in fact due to ice melt or accumulation over LAND (almost all on Antarctic or Greenland). The 70 and 200 m examples were due to large land glaciers forming during glacial periods. Let us stick to those facts.

You have expounded that temperature rise from what had to be a small solar perturbation was than amplified by CO2 with about 800 year lag. Please explain how once the temperature was greatly raised, how the temperature then dropped after a short time (about 10,000 years), and also this drop had a CO2 lag? Are you telling me a small perturbation decrease due to solar effects then had a CO2 generated negative amplification?

Dr Eric,
The significant increase in CO2 about 55 MY ago was almost certainly caused by the Deccan Trap super volcano system which erupted violently for many thousands of years, and emitted millions of cubic km of lava. This event may in fact have been triggered by the asteroid strike at Chicxulub (see: http://docs.google.com/Doc?id=dnc49xz_68c623b7gs&hl=en ). The increase of CO2 was also associated with many other increases, including particulates, acid clouds, water vapor injected into the stratosphere, etc., so the CO2 may not be the cause, but associated with it.

I personally think the particulate material coated ice enough to change albedo and cause massive ice melting. This also caused heating as the albedo change retained more solar heat.

There are several periods in geological history where even higher CO2 levels than 1500 ppm were not associated with higher temperatures, so you really need to be careful when you try to associate CO2 with temperature. I am sure there is some effect, but it is the level of positive feedback we are debating.

Of course, it is the level of positive feedback (known as “sensitivity”) that we are discussing here. I think I made this clear in my first paragraph. And when I did describe sensitivity determination, I used only the ice core data, not the less well founded data associated with the periods periods prior to one million years ago.

In fact, I have not learned yet why we think we know what the CO2 concentrations were prior the the ice core record. I mentioned one value I have seen mentioned for that about 50 My ago, but, I will admit, I don’t know what sort of measurement or theory it came from. I’ll bet you can help me there, so please do, while I also try to figure that one out.

By all means, have a go at tying any one or all of the factors you mention into a viable explanation for the ice core record. In doing so I will be most interested to see how well your ideas explains the observed repetitive cycles of temperature between glacial and interglacial periods as they have been revealed in the ice core sample.

While the GHG and albedo feedback effects, in concert with the Milankovitch cycles, do exactly that, perhaps you can put something together with these other factors might quantitatively explain the ice core record, just as well. No one else has, to date, but don’t let that discourage you.

I am not going to attempt to do that here – even though it might merit a Noble Prize if I could.

@15 Al, OK, I can see how you could have taken my comment to imply that computer models of sensitivity were the best. What I meant, of course, was the opposite, and I think comes through in the rest of my paragragh.

So just for the record, historical measurements are the best indicator of the future. I comment the computer modelers and support their work. But the complexity of the system under investigation is great and they don’t know enough about all of the variables. On the other hand, observations of the past have everything included. of course, even if we don’t understand or even know all the variables. And as I tried to illustrate in my Post, we can extract GHG sensitivities from those observations.

“More on this point. There are no facts that will ever PROVE that a hypothesis is true. For example, in a couple hundred years from now, if the entire world has turnd out to be toast, that “observed fact” would not prove a cause and effect relationships such as described by the hypothesis of AGW. By then, the model of AGW will probably still be intact (in spades in fact), but it will still be just a theory. Scientist know this and you should learn the point – that we advance in science by proposing models and by continuously testing them in order to find the best one.” (My capitalisation).

Yes, Dr Eric, but I am still waiting patiently to find out what would FALSIFY the AGW hypothesis. I am starting to think that your answer to the question will be “nothing”.

Your comment that dT/dC in the ice cords which the Earth was changing between glacial and interglacial states would be about 17 decrease C (of K) makes sense. This would not be the global GHG sensitivity, however, because the temperature variations at the poles are greater than the parallel variations of global averages. We have been able easily track both in the modern era and find that the pole variations are about twice those of the globe. Therefore, if we divide 17 by 2 , we get 8 degree for your starting estimate. This would be the “slow feedback” values (as I explained in my post) because it is being determined over periods of several millenia. From Hansen et al’s analysis of the ice cores I reviewed in my post, they came up with a slow feedback sensitivity of 6.5 degrees C. Therefore, your comment is in close harmony with what I have presented here.

Note also that about half of the slow feedback sensitivity is the fast feedback portion of 3 degrees. That applies to shorter term periods of say several decades or say to the end of the current century. After that the net sensitivity term for change since the beginning of the Industrial Age would be greater as it increases towards 6 degrees C. Either of these values for sensitivity, however, are far too great for comfort.

Your wish that I would have used the “IPCC approach” deserves additional comment. IPCC reports are distillations of the results of scientific studies carried out by other scientists throughout the word. These results are blended into something that is hopefully understandable to policy makers and the public. The results of studies are emphasized with the presumption that these results and associated recommendations come from the best scientific personnel available of the world (and this statement is correct). Now if that’s enough for you, Jim or anyone else, please just read the IPCC reports and accept them. I happen to agree with most of their recommendations both for the reason related above and also because I happen to understand much of the underlying science and have come to similar conclusions.

Now if you chose to distrust the IPCC reports, where do you go next? I would think it would be to understand more of the basic science behind those results and recommendation. That, of course, is what we are trying to do here and what you call a “farce”. So you don’t trust our best scientists views and you think trying to learn more of it yourself is a farce. I would encourage you do reconsider and try either one or the other of these two options. A third option, of course, would be to find some demagogue who would be pleased to tell you want to think.

Dr. Eric, You have not answered my question. What is the reference to the publication where you work presented above, is published? Or if is has not been published, would you confirm it has not been published.

As to my relationship with the IPCC, I have read and studied the physics presented by the IPCC, and believe it is fatally and fundamentally flawed. However, my physics is not good enough to prove this. So I am looking for any discussion of what the IPCC has presented, so that I can try and understand better what the physics means. That is why I was disappointed that you presented an altermative approach. As to whether I distrust the “best scientists”, is a moot point. If the people you refer to have got the science wrong, then I suspect they are not the “best scientists”. I am a believer in Richard Feynman “Science is the belief in the ignorance of experts”. I look at the science which is presented; not the reputation of the presenter. Nullius in Verba.

@33,
Once the CO2 increase is in place, the temperature starts going down BEFORE the CO2 starts dropping. If SMALL changes due to planetary inclination can drive the process, the CO2/feedback concept is not needed. Keep in mind the down trend starts down at a much higher temperature than the uptrend, so the temperature is well above the value that caused positive feedback. If CO2 causes a positive feedback, saying it can also cause a negative feedback at a HIGHER temperature is contradictory. Using the excuse that more CO2 dissolves in the oceans while still at the higher temperature is wrong.

The reason the down slope is slower than up slope is due to the specific gravity variation of seawater. Warm water sits on the surface, cold water sinks. Thus a small amount of warming (due to reduced ice cover caused by planetary tilt), melts some ice and decreases albedo, which raises the surface temperature of the ocean fairly rapidly. The warmer water increases water vapor pressure, giving positive feedback. When the tilt back increases the albedo, the cooling cools the surface fairly rapidly, but the cooler water sinks and replaces the surface with less cool water, so the ocean volume that has to cool is much larger than the volume that has to heat. This slows down the ramp down, due to a smaller feedback down.

First, what is dT/dC? It can not be an expression for sensitivity, which is defined to be a constant value expressing the change in T with each doubling of C.

The value for sensitivity you mention of about 18 degrees seems much to high to me to be real (I hope). If this was meant to be the sensitivity of the polar temperature, it would be in the ball park, as I explained in response #15.

First, Vostok ice records show peak-to-peak _estimated_ variability of only 12C. The number 18C comes out of the fact that the CO2 swing was not 2X either, so the actual “sensitivity” accounts for this.

Second, Vostok ice records contain only d18O as a proxy for temperature. To translate it into temperatures, some poorly-specified calibration relationship is required. The literature is not clear on whether it is “average low troposphere temperature”, or local temperature, I have seen both labels.

Third, it is widely known that AGW theory (aka models) do not exhibit polar amplification for Antarctic, and they have plenty of excuses for this.

Fifth, modern records do not support polar amplification in Arctic either, see:http://www.agu.org/pubs/crossref/2002/2001GL011111.shtml
“Arctic and northern-hemispheric air-temperature trends during the 20th century … are similar, and do not support the predicted polar amplification of global warming. … If long-term trends are accepted as a valid measure of climate change, then the SAT and ice data do not support the proposed polar amplification of global warming.”

Therefore, there is no evidence for polar amplification in neither hemisphere (and especially in Antarctic, where Vostok borehole is situated), such that reducing the ice core observations by half has no justification. This lack of “polar amplification” also explains why ice core temperature scale can be (and was) used interchangeably, either as local or global. Your entire account of the situation is pure misinformation.

Regarding the second step of your adjustments, AGW theorists keep talking about “slow feedbacks” and associated “heat in the pipeline” as opposite to “fast feedback”. However, this entire construction is inconsistent with basic observations.

Regarding “fast feedbacks”, the basic observation is that surface temperatures do not need “several decades” to adjust to radiative forcing. It is well known that when the forcing changes, average weather follows and adjusts in a matter of few months. This effect is commonly known as “seasons”. You would not deny the existence of seasons, would you?

Now, the basic fear from “slow feedback” also doesn’t have much physics behind. The slow feedback is usually explained by changes in global average polar albedo, which is supposed to have drastic effect in long term and amplify the global climate sensitivity by another 3C. However, we all know that ice cups retreat and advance seasonally by whopping 50%, such that seasonal albedo changes vastly exceed the tiny annual difference (of 1-2%). If climate is so sensitive to this tiny annual difference, and the fast time constant of climate is of the order of half year as we know it, what could be the amplification effect of this seasonal albedo change? It should be devastating, while it is not. Therefore, it looks like fears of huge climate sensitivity are highly exaggerated.

In short, you attempt to explain the order of magnitude discrepancy in alleged climate sensitivity to CO2 between instrumental records and ice core records has failed in eyes of jury. The simplest explanation of this discrepancy is that CO2 doesn’t affect climate to any significant degree, and that’s why the CO2=>T relationship is a simple slave function CO2 = f(T).

@42, Hi Dr. Eric,
The surface water is not that cold except possibly very near the poles. In addition the surface salt concentration increasing near the poles (from evaporation) lowers the freezing point, increases the density, and also lowers the temperature of the density reversal point. I need to verify, but I think for temperatures up to the ice location, the surface density is continually increasing with cooling (that is why the thermohaline current goes down there). However, it is the larger surface areas away from the poles that are most affected by GLOBAL temperature variations, and for those the surface temperature is much above freezing.

@44,
This comment “GHG effects also appear to kick in (see the data)”, has no data supporting it. The GHG rises from the warming of the oceans. The temperature continues to rise. Water vapor and cloud effect are much more likely the source of positive feedback, and selecting the GHG was a pure speculation with no support. The argument that models can’t explain the difference otherwise just shows the models can’t handle clouds (which they admit)!

The statement “Another factor you need to consider is that the GHG effect is not linearly related to the temperature change. That is dT/dCO2 is not a constant but is a continuously decreasing value as the concentration of CO2 increases. So at the higher CO2 concentrations that exist during the interglacial periods, dT/dCO2 is not as large as it was in a colder word and, therefore, dT is then more influence by the small effects of orbital changes than it was during the cooler periods.” is astonishing. We are in an interglacial period, thus the CO2 level, even without human contribution, would be in a range of lower sensitivity. At the elevated actual range and projected ones, the sensitivity would be even lower. If a very small tilt variation at 280 ppm has very little direct effect (it did not change average insolation, only caused some selective freezing or melting, thus changed albedo a bit) then how does this very small variations cause a large effect. We have a disconnect here. You imply that CO2 effects are important to pump the temperature up, but they are not able to hold them up with small variations in the same parameter.

I would like to make a general comment here. There is a huge amount of peer reviewed papers with data out there. Along with the data, there is also analysis in the papers. The data may be questioned (how it was obtained, the errors possible, methods of reducing raw data to published form, etc.), but it is data. The analysis generally is just the opinion of the authors. It may be very good analysis, but it is not data. There is no reason sets of data can’t be used by others and their analysis applied, which might be different than the authors (with attention to credit and copyright limits). Peer review does not verify analysis, it verifies data and considers analysis for reasonableness and logic, and consistency with the previous trend of the literature. The discussions in blogs are able to refer to data from any source as long as it is able to be validated, and to re analyze others data any way they please, as long as it also is subject to the same types of criticism as analysis in peer reviewed papers. The fact of being peer reviewed does not make the original analysis valid.

You stated “So the hypothesis does not specify the processes that cause the stated Sensitivity?” As I think was made clear in my Post 6, the processes I believe are operative and generate the sensitivity values I suggested are those described by a model comprised of the Milankovitch cycles along with the dominant positive feedbacks of the Earth’s albedo and the GHG’s.

You then stated that I did not specify “the conditions wherein the hypothesis may be true or false?” What do you mean by the words “true” and “false”? Should assume you mean the literal definitions of those words? If so, are you suggesting that complex systems such as we are considering here can ever be shown to be either true or false beyond all levels of doubt. That cannot happen – I cannot envision conditions or results for which this or any other hypothesis concerning a complex environmental system could be shown to be either true or false in a literal scene. For example, if the world turns into a desert by the end this century that does not “prove” any hypothesis. That result would simply be an observed “fact” that might possibly be used as evidence for the hypothesis of AGW. (Your implication here that an ultimate “truth” can be determined by science leads me to suspect that do not know much about the limitations of the Scientific Method).

And finally you state that I did not provide “any reasons why the Sensitivity changes with time?” I think I did, in fact, do this. The reason, as was described in my Post 6, is that over short periods of time only the fast feedbacks would be apparent and over longer time spans the slower feedbacks would also contribute and thereby increase the overall sensitivity for that longer time span of interest.

If you do not understand or question some of the other aspects of my Post #6, don’t hesitate do bring those detailed points up. Since you are the “scientific brain” representing one of the two halves of this so called “Great Debate”, it would be a good thing if you got a bit more involved in its scientific aspects.

It is impossible to communicate to you the point I was trying to make if we hold difference definitions of the very basic term, sensitivity.

You seem to believe that the magnitude of CO2 sensitivity is lower during interglacial periods than the glacial periods (as indicated by your statement “We are in an interglacial period, thus the CO2 level, even without human contribution, would be in a range of lower sensitivity. At the elevated actual range and projected ones, the sensitivity would be even lower”.

My understanding is that “sensitivity” to CO2 is a constant value that applies the same now just as it did during the glacial period. The term instantaneous change in T with changes in CO2, which we might represent as the derivative, dT/dCO2, is an entirely different quantity that describes the change in T with a change in CO2 at any given point in time. This quantity is not contant and should decrease with increased concentration of CO2. Perhaps this is what you are thinking of when you used the term, sensitivity.

To illustrate: if CO2 doubles from 400 to 8oo ppm, the temperature will increase by X degrees where X is the “sensitivity” of CO2 as defined in Ed’s list of definitions. If CO2 then goes on to double again from 800 to 1600 ppm, the temperature is expected to increase by X degrees again – even though it took a 800 ppm increase in CO2 to do this the second time while it took only 400 ppm increase to do it the first time. So dT/dCO2 does decrease with increase CO2 concentration but the “sensitivity” of CO2 remains constant.

It is difficult to converse unless we are on the same page with respect to the meaning basic terms. If I am mistaken on my understanding of the most important term of all in this debate, sensitivity, please do straighten me out ASAP – so that we all all on the same page. Without that common understanding of definitions, many things we say will indeed seem “astounding” to others.

My most responses to yours comments in 53 are shown below each of yours :

You said “Eric, first you implied your @45 statement was the whole hypothesis. Now, in @52 you say you meant to include other factors. You can’t have it both ways.”

Ed, I only added to my first statement because you seemed to want me to (read your own message, #46) not because I “meant to”. Therefore, and since I can’t have it both ways (whatever that means), let’s just go with my first statement.

You stated “Regarding stating the “conditions” wherein a hypothesis may be true or false, you should understand the example that Newton’s law is considered true at non-relativistic speeds and false at relativistic speeds. Every hypothesis has boundary conditions.”

Newton’s equations became to be known as “Laws” because they are simple to test and have always been observed to be true. Thus the Laws of Gravity became a simple way of referring to his set of equations or observable facts. Note that there is no accepted “Theory of Gravity” – as you know since even your hero, Albert, gave up on that project. I wonder what his “boundary conditions” where for defense of his successful explanation of the photo electric were, however. Perhaps you could look that up.

If you are looking for historic precedence concerning the “boundary conditions” of more complex scientific questions, perhaps you should also look up what was used in previous environmental issues such as the effects of second hand smoke, mercury, lead or cadmium on human beings. The lawyers involved in those law cases might have been pleased to provide you with the “boundary conditions” on those points – provided they were given the time and money to do the job.

In other words I don’t think I’ll have the “boundary conditions” you require by tomorrow morning. So perhaps this will give the Webmaster sufficient reason to declare victory and go home.

Lastly, you stated that “@00 reads more like an article in National Geographic than a paper in atmospheric science”.

Thank you for the kind comment, Ed. I am doing my best here to communicate with the audience many of whom would not want to read a scientific paper (for those that do, however, I have more than a hundred listed in my resume on ericgrimsrud.com. Be my guest.

While saying good night to you now, Ed, I am still wondering when you are going to start acting more like a scientist rather than a lawyer.

I am not sure anymore at what level we are trying the CO2. Dr. Eric wrote:

“As the Earth goes through its subtle variations of distance, tilt and precession as it revolves about the Sun, slight changes in the solar intensity in the both hemispheres occur. What happens in the Northern Hemisphere is most important because of its greater land masses. If the Northern Hemisphere happens to have a worse than average summer, the ice on it tends to grow. If it has a better than average summer, the ice on it tend to retreat. These changes in ice area cause large changes in the Earth’s albedo. In this case, we call this change a “positive feedback” because the albedo change reinforces the initial direction of change. Only after the information of the ice cores started to be revealed in the 1990’s did we realize the calculations of Milancovitch back in the 1920’s where of great importance.”

I am sorry, but all this verbage does not have any relation to reality nor to Standard Theory of Ice Ages. I wonder if Dr.Eric ever read any real articles on the subject.

First, the climate is a global system. However, the Milankovitch forcing never exceeds 1% in variation on global scale. This variation is widely considered as non-essential and negligible. To support the theory, Milankovitch (1941) suggested that changes in summer insolation in certain selected spots might affect ice recession, with the critical zone suggested at 65N and 65S. The NH is critical not because NH has more land, it is because the nearly continuous land in NH happens to be at 65N, while SH has only water past this point, such that ice has no land to advance.

The major serious attempt to link the pathetically small global forcing from Milankovitch cycles was published in 1992 by Imbrie et al (18 authors total) in Paleoceanography.

It is absolutely important to note that this pioneering work does not consider the CO2 forcing as any important player. All theory was built on interplay of shifts in ocean patterns, winds, fresh water influxes, and 4-stage propagating response. Their CONCLUSION section does not mention CO2 even once! So, when someone says that “we cannot explain ice ages without CO2 radiative forcing”, it is a lie.

The CO2 “forcing” was incorporated much later, apparently by architects of AGW hoax. The entire “theory” is extremely complex, involves many-many special conditions and assumptions about relative position of seas and lands, etc., obviously every element is highly speculative and subject a wide range of parameterization, see publications of Ruddiman and some French folks.

The whole thing with Milankovitch forcing was later challenged by some scientists on the basis of formal analysis of time series:

“A number of records commonly described as showing control of climate change by Milankovitch insolation forcing are re-examined. The fraction of the record variance attributable to orbital changes never exceeds 20%. In no case, including a tuned core, do these forcing bands explain the overall behavior of the records. At zero order, all records are consistent with stochastic models of varying complexity with a small superimposed Milankovitch response, mainly in the obliquity band. Evidence cited to support the hypothesis that the 100 Ka glacial/interglacial cycles are controlled by the quasi-periodic insolation forcing is likely indistinguishable from chance,

I would completely agree with the above – it is all simple noise, nothing much more.

In short, as presented by Dr.Eric, the account of Milankovitch theory of ice ages does not qualify even for a 8-th grade essay for a class in natural sciences. For general (but still heavy AGW-centric) education on the subject, please visit this site and read the papers:

“In short, as presented by Dr.Eric, the account of Milankovitch theory of ice ages does not qualify even for a 8-th grade essay for a class in natural sciences. For general (but still heavy AGW-centric) education on the subject, please visit this site and read the papers. In short, as presented by Dr.Eric, the account of Milankovitch theory of ice ages does not qualify even for a 8-th grade essay for a class in natural sciences. For general (but still heavy AGW-centric) education on the subject, please visit this site and read the papers:

Upon visiting the site you recommended, I found several short abstracts (not full papers) of recent scholarly work in which details of the Milankovitch Cycles were being examined, challenged and discussed. As always in science, good ideas are continuously being perfected, as they should be. I also noted that one of the most recent abstracts listed began with “The Milankovitch hypothesis is widely held to be one of the cornerstones of climate science.”

Al, please try to have your own references better support what you say. I beg to differ with you. I think the Milankovitch idea does merit an 8th grade essay.

In my view as a physicist, there have been many good questions raised here. And, to his credit, for the most part, Dr. Eric has respectfully tried to respond.

It seems to me, though, that most of us are missing the Big Picture. Almost all of the questions and critiques are based on how the data (e.g. changes on global temperatures) is being interpreted.

Please correct me if I’m wrong here, but I don’t see anyone questioning the veracity of the underlying data.

I do.

The simple fact is that if the underlying data is inaccurate, no amount of massaging (or interpretation) will make it scientifically meaningful. (Of course that is a premise that some AGW proponents might disagree with!)

Maybe that is why my repeated simple question to Dr. Berg has been so far unanswered. I will try again:

Dr. Eric: What is the “official” average global temperature for the year 1800?

@54,
I want to expand a bit on what point I was trying to make. There are multiple causes of large average temperature variations that have nothing to do with GHG effects. These include seasons (several months long), large volcanoes (typically one to several years long), and large ocean cycles (decades long). These cause typically larger temperature variations down than the Milankovitch cycles direct effects, but are not as long lasting. In addition, there are cycles with very deep temperature drops lasting several hundreds of years or more (e.g., LIA), that may be caused by solar variation. They also do not trigger a drop from an interglacial period to a glacial period. You have implied that the generally smaller effect from Milankovitch cycles starts the downturn, but the CO2 is a significant feedback amplifying the effect. How do you make these facts of other larger temporary drops agree with your claims.

The logical answer to me is that the dT/dCO2 component is small and not a significant driver of the process. If the small but longer lasting drop from Milankovitch cycles eventually causes the total drop without much help from CO2, this would be consistent with the observed cycles. The concept of a trigger effect resulting in boosting the effect is falsified by the lack of continuing drop due to the other drivers.

More on 63:
I think we have agreed that about 50% of any excess CO2 from any selected level is removed in a time of 30 to 100 years. This would imply that if cooling from any source lasted a good fraction of this time period (and multi-decadal ocean current variations and the LIA and others periods did this cooling), then any CO2 feedback to continue the drop would be activated. It has not and does not appear to have done so.

@56, Al.
I don’t know if Milankovitch cycles are significant drivers of the 40k year and 100k year glacial to interglacial cycles. However, the cycles happen, and the tilt and other orbit variations seem to be in the correct phases to have some effect. I would like to know what are the drivers if Milankovitch cycles are not significant causes. However whatever the causes of the cycles are, it does not appear to me that CO2 is a major contributor.

I am being misinterpreted. Dr. Eric seems to have come up with an entirely new way of estimating climate sensitivity. I have not seen this anywhere in the literature before. How valid is this approach? I do not have sufficient knowledge to do a proper critique of the analysis. But there are others who do. This is the whole point of peer review, publication, etc. To get new ideas out to the scientific community as a whole, so these ideas can be properly evaluated. That is clearly not possible with Dr. Eric’s treatise.

I have discussed CAGW on places like RealClimate, and they insist, quite rightly in my opinion, that before ideas can be given serious consideration, they need to be peer reviewed and published in a scientific journal. If Dr. Eric is springing some entirely new idea that the scientific community has never seen before, and expects this blog to assess how valid it is, then that is what I have called it. A farce. It simply cannot happen.

“The most important point I have tried to make here in this Post 6 is that the Sensitivity of CO2 is somewhere between about 3 and 6 degrees C depending on whether we are talking about a short term (say several decades) or a longer term (say several centuries) period. This deduction has come from direct measurements of the past via the ice core samples.”

In my post, I provided a bare-bones summary of concept of the Milankovitch cycles, which as one of Al’s expert references stated has been the “cornerstone” of climate research, because I have the impression that Al reference is correct. There certainly are other contributions to climate change in addition to the slight changes in orbital forcings of those cycles. For example, volcanoes certainly emit lots of CO2 and if frequent and large enough, can also affect climate by adding lots of CO2, causing warming, or particulate matter, causing cooling, over an extended period. These factors could either add to or reverse a trend favored by the M Cycles. Nevertheless, it does appear that an important initiator of climate changes during this delicately balance period of glacial and interglacials has been the M Cycles.

NOW NOTE THIS: As to the importance of the albedo and GHG feedback effects, it does not change things we find that other factors are even more important that the M Cycles in causing an initial change in temperature. Please read that sentence again so that we can get back onto the main point of my Post 6.

Now if we could get back to the main main point related above, whatever the total forces are that initial a change in the temperture of the Earth, the ice core sample clear tell us that those changes are then followed by changes in the albedo and the GHG concentrations. Basic principles of physics then also tells us that both of these changes will then provide positive feedback, thereby amplifying the trend to either higher or lower temperatures. If anyone would like to challenge the validity of my last sentence, first do just a bit of study of the terms, albedo and the greenhouse effect, or then ask me to explain any questions concerning them that you might have).

In summary, let’s not get our eye of the ball. I do want to learn more about the M Cycles and other factors that could have initiate the changes in albedo and the GHG forcing as revealed in the ice core samples and those discussions are fine. My point here is to remind us that these factors will have very little to do with the magnitudes of the albedo and greenhouse gas feedbacks observed after those initial changes occur.

Ed, I suggest we now start another side bar catagory called the Milankovitch Cycles where folks more expert than I can hammer things out and the rest of us can watch.

It is difficult to converse unless we are on the same page with respect to the meaning basic terms. If I am mistaken on my understanding of the most important term of all in this debate, sensitivity, please do straighten me out ASAP – so that we all all on the same page. Without that common understanding of definitions, many things we say will indeed seem “astounding” to others.

No we have absolutely no common understanding about the basic definitions .
Actually this is not surprising because you have never submitted any definition .
So unless you believe in mind reading , there is exactly 0 chance that somebody can guess non existing definitions .

I ask for the Xth time the fundamental 2 questions :

– In dT/dCO2 , what is T ? Definition as accurate as possible . Equations are welcome .

– What was the cloudiness 100 000 years ago ? Definition : cloudiness = surface covered by clouds / total surface of the Earth

Without answer on these 2 fundamental questions the whole post is just meaningless babbling that has not even the vocabulary in common with science .

It seems fair to me to ask why you want it. Do you not realize that the very subtle orbital forcing factors became relevant to climate change only during the last very delicately balanced glacial-interglacial periods of the last few million years?

This one is easy . How do you know that ? How do you know that the difference between (unknown) orbital factors 65 My ago and today was “very subtle” ?
It’s because I can’t see how you could have made statements like the one above WITHOUT knowing what the orbital parameters 65My ago were that I ask .
As an aside , “delicately balanced glacial-interglacial periods ” is surely nice from the litterary point of view but I see neither delicacy nor balance in those brutal variations .

Btw it is for me no mystery why there was much CO2 . It’s simply because it was so hot (if we assume that it was “hot” everywhere in the oceans what I don’t know) . This is just the good old trivial Henry’s law that has been known for some 200 years .

T stands for Temperature and I used it in answering questions from others who used it first, without definition, I presume because they assumed that I would know what T stood for. In future, if I use that symbol I will be sure to defined it,

Thanks , very kind . With this powerful definition I can now help you along a bit .
So if we accept that the O18 proxy gives us a more or less accurate temperature at the South Pole , then dT/dC is the variation of the temperature at the South Pole 100 000 years ago divided by the variation of CO2 concentration at the South Pole 100 000 years ago . We will skip the annoying fact that the O18 actually doesn’t give us this temperature 100 000 years ago but at some random date more or less near to 100 000 years ago .
OK now why this dT/dC measured at the South Pole would have anything to do with the climate on the Earth ? For example did it rain much or little ? How warm or cold were the ocean currents and where did they circulate ?

And not to forget my third fundamental question that you still didn’t answer .

“The most important point I have tried to make here in this Post 6 is that the Sensitivity of CO2 is somewhere between about 3 and 6 degrees C depending on whether we are talking about a short term (say several decades) or a longer term (say several centuries) period. This deduction has come from direct measurements of the past via the ice core samples.”

is without any supportable foundation. It is the result of analysis on limited data but with many assumptions. The main assumption always seems to be: look for those things we understand and see if they can give the result without CO2 effects (and since they do not understand clouds, particulates, solar activity other than direct insolation, etc, that means they really don’t understand actual causes). They then conclude they can’t get the effect without CO2 being the dominate driver with their (simplified) assumptions. Then they assume the CO2 is the main cause of the heating. Assuming the CO2 is the cause of heating they conclude CO2 is the cause of heating. Circular reasoning.

In the case of heating from 1850 to the present, their assumptions would have resulted in a much larger heating than was actually observed. Now particulate pollution effects are added so that two large effects nearly cancel, and the small difference of two unknown large numbers gives exactly the right answer. The amount of particulates is adjusted to make it work out. Hard to accept that, especially when the temperature rise followed the well known long lasting unusually cold period called the Little Ice Age, and part, or most, of the heating was actually a recovery to more typical holocene temperature.

Another point is that ice cores going back long enough are found at only a small number of locations (mainly Greenland and Antarctica). If we believe these ice core records as representing global trends, we see large swings in those records of up to 2 C several times with time constants of 50 to several hundred years throughout the holocene. These are significantly larger than the present swing. I don’t think we had large scale human burning of fossil fuels those other times, so what is the cause?

A final point for this entry has to do with the long term trends quoted. These would require some clear excess energy storage process. Since the present CO2 is the highest level and fastest rising over the last several millions of years, this storage should be clearly observable in the oceans (the only place it could hide), especially since the temperature is not presently on a rising trend. Since 2002, the added energy to the oceans have been near flat (and data before that is highly limited and questionable). There is no suitable storage.

@82,
The ice cores going back to the previous several glacial/interglacial cycles only appear in a small number of locations, all over land, and almost all near the poles. If we look at the ice core data alone, my comments are absolutely valid. If you add ocean floor cores, this increases the number of locations, but these also show the couple of degree swings in similar time scales as the ice cores. Going from those few locations to a global average is not supportable. If it were, the arguments against the MWP and other warm periods, as well as the LIA and other cool periods in the present holocene would be immediately overturned (you can argue this with Mann). I do believe in some correlation globally, but not just from the ice cores.

Please respond to my specific questions or claims if you would, or not, but do not attribute my statements to hyperbole. I try to argue the facts and data, and do not accept analysis of others just because it is in the peer reviewed literature. I made valid statements as I see them. I read Hansen, et. al., and concluded he is not logically supporting his conclusions, but is making unsupportable assumptions to get there.

Dr. Eric @57, I understand that my comments might be distracting (or destructing?) to your concentration on refining your AGW hypothesis, so you are under no obligation to reply. However, it is now clear that you haven’t read any literature on Milanlovitch hypothesis other than first sentences in abstracts.

From you account of Milankovitch theory (as published here, @00), it is apparent that you are completely unfamiliar with complexity of elements that are needed to explain glacial ages. To my own surprise, I found a strain of works that used no CO2 what-so-ever to explain ice ages within Milankovitch framework. Unfortunately, this complexity and fuzziness of elements of the theory allows to squeeze in almost anything. If I wanted, I could squeeze in an influence of Moonshine on ice sheet growth, including growth of telegraph poles, or show a defining role of green cheese if somebody asks me. So, you allusion to “refinement of the theory” is wasted, it was not a refining, it was an opportunity for AGW.

You found that “The Milankovitch hypothesis is widely held to be one of the cornerstones of climate science.” Where did I disagree with that? BTW, flat Earth resting on three elephants was also a widely held theory in certain ages…

I also wonder, why do you think that this statement contradicts my findings that incorporation of CO2 forcing is an unnecessary element in that theory, and therefore is not a “major driving force” as it is “widely held” today by AGW proponents?

Regarding merits for 8th graders and their environmental essays, as long as they can figure out where the ablation/sublimation boundary forms in turbulent atmosphere 100,000 ago, I am all for it.

Please!! Your comments in the first paragraph of item 79 constitute the very definition of hyperbole (look a the meaning of this word below if you don’t happen to know what it is). When someone says something has NO foundation, when that something very probably does have a foundation, and then that someone admits in the next sentence what that foundation is !!! – that is hyperbole. Or perhaps you need to also need to relearn the definition of the word, NO (also provided below).

Yet another response you might take would be to simply recognize this egotistical manner of expression and try not to use it. It’s fine with me if you don’t trust anybody but yourself, but you might try to treat others with some respect with you want to have an exchange with them. Just because you think Hansen’s work is shit does not mean that it really is or that I should take your word for it. Pardon my frankness, but I am begining to think you are like egotistical, impolite bully.

On the chance that this might help repair my impression of you, could you possibly provide me with a list of your professional accomplishment and especially your peer-reviewed articles so that I can inspect them. Now if you tell me that you would not and have not using the peer-reviewed literature for describing your work – possibly because all of it, also, is nothing but shit, that response would be all I need to know where you are coming from. In any case, its is now your turn to respond to my request.

some definitions to save you the trouble are:
hyperbole: to exaggerate in order the minimize or depreciate
no: none, zero, as in zip.

Yes, your rough number do generally represent what I am claiming. The factor of 2.0 which changes the polar variation to an estimate of average global variations comes from recent observations of polar and global temperatures by modern thermometers – the former is typically about twice he latter. Also, I don’t know what you mean by “other messaging” because to my knowledge there is none.

From your rough numbers the long term sensitive looks like it would be about 8 degrees C, while Hansen gets 6.5 degrees C using all of the data. Your choice of the very highest CO2 reading of 300 instead of say about 290 which is what I see in Fig 2 would bring your number closer to Hansen’s.

But in general, yes, you appear to be understanding what I have presented.

“The factor of 2.0 which changes the polar variation to an estimate of average global variations comes from recent observations of polar and global temperatures by modern thermometers – the former is typically about twice he latter.”

To refresh, after presenting published and peer-reviewed literature, I summarized for easiness:“Therefore, there is no evidence for polar amplification in neither hemisphere (and especially in Antarctic, where Vostok borehole is situated), such that reducing the ice core observations by half has no justification.”

If the factor of 2.0 is not the best value to use, please point us all to a more accurate value along with the evidence supporting it, and we will gladly use it instead. I would guess at this point, however, that the updated value you might thereby provide will not change things very much. Nevertheless, please do let us know when you have a better value and thanks for looking into this detail.

In order to make any use of your hypothesis, we must have a starting point. Simply saying doubling CO2 will increase Temperature by 6 C is not enough. We also need a starting value for CO2 and (its equilibrium) Temperature in order to predict anything.

To put it another way, begin with any value of CO2 you wish to use as a reference value and then state the equilibrium Temperature your hypothesis predicts will occur after several centuries.

(In a more mathematical form, if we integrate a rate of change we still need to have a reference point in order to predict a value after an interval of time.)

@76 Dr Eric. Thanks for the reply. So you have not yet given an example of something which would falsify AGW. I was expecting something like “if global average temperatures fall by X degC over a period of Y years then AGW will be falsified”. I just sense a reluctance from you, and others holding your views, to commit to something measurable and testable ie to expose the hypothesis to genuine scientific scrutiny and verification.

@81Also, can anyone help Tom with his other question “What was the cloudiness 65 My ago and 100 000 years ago ?”. Until I have a reason to what to know, I will spend my time on other things. If your point, Tom, is to prove that I don’t know this and lots of other things about the history of the universe, I’ll plead guilty immediately in the hope of avoiding trials designed for that purpose.

I am puzzled.
Either you deliberately evacuate relevant questions or, and that would be really serious, you don’t understand what are the relevant questions.

To put you at rest, of course the point is not to show that you ignore lots and lots of things – this would be a trivial and little interesting result.
The point is that you not only ignore the relevant but you see to not to knw why they are relevant.

So I will try to be even more pedagogical than I already was and hope that you will understand why these questions are not only relevant but fundamental to the issue.

1) You have put a graph estimating the temperature at at some location 65 My ago.
2) Obviously you want to use this graph to derive something about CO2 in this distant past 65 My ago. And indeed you talk about dT/dCO2 at that (unknown) location.
3) The orbital parameters and even more the cloudiness impact temperatures an order of magnitude more than the CO2.
4) Therefore to find a tiny CO2 signal in the temperature at that mysterious location, tou ABSOLUTELY NEED to know higher order effects.
5) If you don’t then you can say nothing very scientific about this temperature and even less something about the tiny effect due to CO2 variation.

And to be complete a third question :
– Why should this local temperature at an unknown spot some 65 My ago have anything to do with the climate 65 My ago.

If you either ignore these answers or don’t want to consider the questions on effects that play at a much higher order of magnitude than what you want to analyse, then I suggest that you remove this graph because it is completely irrelevant and useless to the topic discussed here.
E.g what are the CO2 effects on the climate today

@86 ,
I want to add that all publications done at NASA were internally peer reviewed at NASA even before they were submitted for journal publication. Tech briefs, patents, and technical talks were also internally peer reviewed before release. I published an average of about 1 journal publication (or NASA technical paper) per year while I was at NASA, and in addition, gave an average of about 1 national or international conference paper per year, most with published proceedings. I have 11 issued patents and 2 pending, and about 20 tech briefs on a wide range of topics. I have also given over 20 lectures to schools such as Princeton and others. However, much of the work I did was in cooperation with aircraft companies doing tests at NASA facilities, so the results were proprietary, and not published in the open literature.

I am beginning to think you do not understand mathematics. In your whole @94, you still did not fully answer what I thought was a simple question. Therefore, I will attempt to make the issue more clear.

You use a doubling of CO2 to imply a fixed increase in Temperature. This implies a logarithmic relationship as follows (where I will use natural logarithms):

T – T0 = k Log( CO2 / CO20 ) ………………………… (1)

Where T0 and CO20 are reference values and k is a constant to be determined. You have indicated you would like to use CO20 = 280 ppm as your reference value. The problem is you did not specify your corresponding T0 reference value.

We can find k from your (long-term) hypothesis (1) as follows:

6 C = k Log(2) = k * 0.693 …………………………. (2)

or k = 8.66 C ……………………………………… (3)

Now, if we go back to (1) and set CO2 = CO20, we get:

T – To = 0

In other words, at your value of CO2 = 280 ppm, T = T0 but we still need to know your T0.

Would you please confirm that (1), (2), and (3) is the proper formulation of your hypothesis (for longer time scales of several centuries), and would you please tell us what equilibrium or reference Temperature, T0, corresponds to CO2 = 280 ppm?

Sorry , I am not sure if my first post got through as I had to edit it for several typing errors.
So here goes the answer to Eric’s question and questions to him :

Also, can anyone help Tom with his other question “What was the cloudiness 65 My ago and 100 000 years ago ?”. Until I have a reason to what to know, I will spend my time on other things. If your point, Tom, is to prove that I don’t know this and lots of other things about the history of the universe, I’ll plead guilty immediately in the hope of avoiding trials designed for that purpose.

I am puzzled.
Either you deliberately evacuate relevant questions or, and that would be really bad, you don’t understand what are the relevant questions.

To put you at rest, of course the point is not to show that you ignore lots and lots of things – this would be a trivial and little interesting result.
The worrying point is that you not only ignore the relevant things but you seem not to know why they are relevant.

So I will try to be even more pedagogical than I already was and hope that you will understand why these questions are not only relevant but fundamental to the issue.

1) You have put a graph estimating the temperature at some location 65 My ago.
2) Obviously you want to use this graph to derive something about CO2 in this distant past 65 My ago. And indeed you talk about dT/dCO2 at that (unknown) location.
3) The orbital parameters and the cloudiness even more , impact temperatures an order of magnitude more than the CO2.
4) Therefore to find a tiny CO2 signal in the temperature at that mysterious location 65 My ago , you ABSOLUTELY NEED to know the higher order effects.
5) If you don’t have this knowledge then you can say nothing very scientific about this temperature and even less something about the tiny effect due to CO2 variation.

Hence the 2 fundamental questions :

– What was the cloudiness 65 My ago ?
– What were the orbital parameters 65 My ago ?

And to be complete a third question :
– Why should this local temperature at an unknown spot some 65 My ago have anything to do with the climate 65 My ago ?

If you either ignore these answers or don’t want to consider the questions concerning effects that play at a much higher order of magnitude than what you want to analyse, then I suggest that you remove this graph because , as I demonstrated above , it is completely irrelevant and useless to the topic discussed here.
E.g what are the CO2 effects on the climate today .

I hope it is very clear why this questions have to be answered if one wants to say anything about the climate 65 My ao.
Of course the same questions apply for the whole past with a decreasing importance of the orbital parameters.

Stan @112, you wrote: “… most AGW opponents, including the ones here, seem to acknowledge that CO2 is a GHG and that it is increasing”.

As I can read between your lines, you want to say that increasing concentration of GHG must lead to proportional increase in magnitude of GH effect. There is a leap in logic. Given the complex vertical temperature profile of atmosphere and complex highly-variable absorption spectrum of dilute gases, this implied relationship is not necessarily true.

You also say: “if it were clearly demonstrated that the average global temperature over the next year … returned to a pre-industrial level”
This is so called “argument of absurd” fallacy. You should recognize this.

You said: “..and simple calculus equations allow you to demonstrate its effect on radiative forcing.”

Please do your simple calculus demonstration, it will be fun to watch.

Dr.Eric @100, you ask: “In the meantime, tell us what you think it should be and we’ll use it instead.”

I already told you 3 (three!!!) times, @95, @89, and @47:
“Therefore, there is no evidence for polar amplification in neither hemisphere (and especially in Antarctic, where Vostok borehole is situated), such that reducing the ice core observations by half has no justification.”

Which part of “no polar amplification” and “reducing … has no justification” was not clear in my texts? Are you having a difficulty to understand that “no correction” means “correction factor of 1.000”?

I will respond here with comments posted after what you have called “pedagogical” remarks. Your comments are in quotes ” “.

“So I will try to be even more pedagogical than I already was and hope that you will understand why these questions are not only relevant but fundamental to the issue.

“1) You have put a graph estimating the temperature at some location 65 My ago. ”

that is true.

“2) Obviously you want to use this graph to derive something about CO2 in this distant past 65 My ago. And indeed you talk about dT/dCO2 at that (unknown) location.”

Why is that obvious? So far I have used this figure just to put the glacial and interglacier period into temporal perspective. If and when I do carefully consider any quantitative details that might be revealed in the first half of this figure, I will then provide appropriate details. At present I don’t even know the details of whereestimates of CO2 concentrations in the ancient atmosphere come from. But I look forward to finding out soon.

“3) The orbital parameters and the cloudiness even more , impact temperatures an order of magnitude more than the CO2. ”

Really? And I assume you are still talking about the ancient atmosphere about 50Mys ago? I sure didn’t know that. In fact, I don’t believe it. Since you are the one making this claim perhaps you could share your reference with me?

“4) Therefore to find a tiny CO2 signal in the temperature at that mysterious location 65 My ago , you ABSOLUTELY NEED to know the higher order effects.”

If by high order effects you mean to include the subtle variations of the Milankovitch Cycles, I don’t believe you (as stated above), so, no, I don’t think I would include them , I would ignore them – that is, even if I were to discuss the details of climate during that period, which I have not yet.

“5) If you don’t have this knowledge then you can say nothing very scientific about this temperature and even less something about the tiny effect due to CO2 variation.”

If and when I discuss the temperature of that more ancients period, I think I would be saying “nothing very scientific” about temperature if I thought the slight orbital changes of the Earth constituted anything more than a tiny bit of noise to the effects of the more dominant factors of that era.

Concerning the fundamental questions you then ask: I will reserve the right here to not go on other people’s wild goose chases when I think going there would be a wild goose chase. For example, if someone asks me how many angels can sit on the head of a pin, my response would be : I don’t know. My response to your last two fundamental questions is similar. There certainly are answers to each, but I don’t know what they are. In addition, I am not even sure if the sage advice of Yogi Berra, “you could look it up” even applies here.

If the atmosphere had no CO2, all of the other feedback factors would also change, of course. So, for starters lets assume, because it would be so cold, that there would be no water vapor, no clouds, no other GHG’s – that is nothing in the atmosphere that would absorb IR radiation – just O2, N2 and Ar. That calculation is easy to do, have done many times for classes and, as I recall it comes out to be about -15 degrees C. Thus the real world is about 30 degrees C higher (fortunately, while recalling that too much of a good thing is also not good – just as if I put on a coat right now, I would get too hot).

Dr. Eric @123 wrote: “If the atmosphere had no CO2, all of the other feedback factors would also change, of course. So, for starters lets assume, because it would be so cold, that there would be no water vapor, no clouds, no other GHG’s”

Realistically speaking, even rock-solid ice has a substantial vapor pressure, otherwise it would be impossible to dry washed linens outdoor at -30C. More, you keep forgetting that equatorial waters would not freeze, they do only in models. Therefore, there will be still plenty of water vapor even without CO2. So the question of Dr.Ed was really ambiguous.

Dr.Eric continues under an assumption “… no other GHG’s – that is nothing in the atmosphere that would absorb IR radiation – just O2, N2 and Ar. That calculation is easy to do, have done many times for classes and, as I recall it comes out to be about -15 degrees C.”

First, I noticed that Dr. Eric is avoiding the term “temperature”. Why it would be so? Maybe because his “easy to do calculations” can be easy only under totally unrealistic conditions?

Dr. Eric, there is now a dedicated thread about “GHG effect”. Why don’t you break the ground on “G” thread with your calculations, with your temperature definition and your assumptions that go into the easy “-15C” number?

@127, Eric, OK, I will add your suggestion as Hypothesis C, making two alternative hypotheses, as follows:

Hypothesis B:

If Temperature increases by about 6C (for any reason whatever) and we wait several centuries then the CO2 will increase by about 150 to 280 ppm, and
also, vice versa, if Temperature decreases by about 6C (no matter what the cause) and we wait several centuries then CO2 will decrease by about 150 to 280 ppm.

Hypothesis C:

If Temperature increases by about 6C (for any reason whatever) and we wait several centuries then the CO2 will double and also, vice versa, if Temperature decreases by about 6C (no matter what the cause) and we wait several centuries then CO2 will halve.

After rereading my comment #130, I should add the following: D-O cycles and Heinrich events are likely the same cycles, although at, respectively, inter-glacial vs galcial periods. They involve rapid temperature jumps, up and down, and last for hundreds of years in one temperature mode, rel. high or low. The dT’s during Heinrich events have tended to be sharper snd greater than D-O cycles. The latter, on a global scale, have involved dT(s) of approx. 1-2*C, globally averaged, with much higher dT(s)’s at higher latitudes. Heinrich events during glacial times times typically are characterized by dT(s)’s of 2 to 4 *C (globally averaged) and by relatively more violent climate changes than D-O cycles. The most recent paleoclimatological manifestations are the D-O cycles episodes of: the Roman warm period, the brief Dark Age cool period, the Medieval Warm Period, the Little Ice Age, and the (piddling) Modern Warm Period, 1735-…2001? For a book heavily focusing on these cycles and containing refences to hundreds of peer-reviewed papers supporting both their existence, magnitude and global nature, see/buy (the awkwardly titled) “Unstoppable Global Warming: Every 1500 Years,” by S. Fred Singer and Dennis T. Avery (Rowman & Littlefield, 2007).

And the problem these cycles both pose for the AGW Theory is: Either the forcings they imply [in W/m^2] are far greater than the “small fraction of a W/m^2” Hansen et. al. say applied during extended I-G or G periods of no significant GHG change, or, Hansen et. al. and their “models” have completely failed to take into account the magnitude of non-GHG forced “internal” climate variability. But that means that their claims that the only way the enormous G-IG and IG-G dT’s (and other large climate effects) can be accounted for is by the utterly small GHG changes due solely to a miniscule initial Milankovich orbital forcing (= according to Hansen et. al. 2008) of a “negliible fraction of ! a W/m^2) are implausible, to say the least. And that this is “settled” science; while D-O and Heinrich events involving relatively large dT’s with (as they are committed to claiming) no dGHGs and no obital forcing at all, is, what?, non-existent?, or, is just mere internal variation? But they can’t claim that these events were nonexistent, given the overwhelming empirical evidence supporting them. And they can’t accept that they were mere “internal” variations, because…? To admit that the magnitude of internal climate variation implied by D-O and Heinrich events (especially as regards changes in dT(s)) is generated without global radiative “imbalances,” would totally undermine the fundamental claim of Hansen et. al., viz., that the only reasonable way to correlate, and therefore explain, the relation between dGHSs (+ their feedbacks) and dT(s)’s is to assume negligible internal variation (=’s no total climate system energy change, perhaps just redistribution), precisley as they always do, and attribute the climate changes to a ridiculously high climate sensitivity to changes in GHG forcing, especially that of CO2. But, since everything in the AGW Theory is run through the node of changes in global surface temperature change, no matter how small., why would not any external forcing of Earth’s climate energy system, or alternatively, any internal rearrangement of heat toward an increase in dT(s), spark a huge upward (or downward – Hansen et. al. rarely talk about going from hot to cold) spiral, of the magnitude they attribute to ice age/interglacial transitions?

@1193) The orbital parameters and the cloudiness even more , impact temperatures an order of magnitude more than the CO2. ”

Really? And I assume you are still talking about the ancient atmosphere about 50Mys ago? I sure didn’t know that. In fact, I don’t believe it. Since you are the one making this claim perhaps you could share your reference with me?

Yes , really ! You see, there are many relevant things you must learn .
It is surprising that you need references for something that is trivial .
But here we go as it seems to be necessary .
The impact on radiative fluxes for a CO2 doubling is estimated around 3 W/m² (reference IPCC) .
The main factor of albedo is cloudiness and especially cloudiness at equator where the system is most violently out of radiative equilibrium .
The average cooling effect of clouds is estimated (today) around 10 W/m² but can go regionaly as high as 100 W/m² (see f.exhttp://www.sciencemag.org/cgi/content/abstract/243/4887/57) .
So yes , really , the cloudiness is a much stronger driver of temperatures than CO2.
You may decide to ignore it but I wonder what you think about scientists who ignore high order factors and pretend to extract a signal which is much weaker than these high order factors .
Clear now ?

“4) Therefore to find a tiny CO2 signal in the temperature at that mysterious location 65 My ago , you ABSOLUTELY NEED to know the higher order effects.”

If by high order effects you mean to include the subtle variations of the Milankovitch Cycles, I don’t believe you (as stated above), so, no, I don’t think I would include them , I would ignore them – that is, even if I were to discuss the details of climate during that period, which I have not yet.

Sorry but this again shows a rather deep misunderstanding of the factors at play .
I have explained the role of the cloudiness above .
Now about Milankovitch (there is a thread opened now so you will probably learn more details in this thread) .
Here just some general knowledge .
The simulations of an N body gravitationaly coupled system (like the Solar system) can only be done for times of a few millions years .
That means that the major orbital parameters (excentricity and obliquity) can only be known for short times .
As the Milankovich theory is based on these variations , it is only valid for short times .
The fact that you evoke it for a period of 65 My ago where it is invalid , shows that you didn’t really look at what this means .
Actually the Solar system being chaotic (this is the reason why these parameters can’t be computed for long times with any reasonable accuracy) , for longer times (>1 My) strange and non understood effects appear .
For instance Saturn seems to affect the Earth’s obliquity much more than Jupiter even if it is farther and less massive . We don’t know why it is so neither whether it was always so .
But as you ignore all the above , you handwave it away .
Talking about “subtle variations of Milankovitch Cycles 65 My ago” just shows that you don’t know what you are talking about (in this particular domain) .

Concerning the fundamental questions you then ask: I will reserve the right here to not go on other people’s wild goose chases when I think going there would be a wild goose chase.

OK let me tell you Eric that after that you lost any scientific credibility with me and probably many others .
I have patiently explained to you that cloudiness and orbital parameters (obliquity and excentricity) were fundamental parameters for the climat in general and 65 My ago in particular .
I have explained why and showed that these fundamental questions must be answered if one wants to use data from the very far past to support any climatic theory .
You have perfectly the right to say that knowing anything about the quantity of Solar energy arriving to the Earth is a “wild goose chase” .
But it is mindboggling that somebody would say that .

I don’t know why Ed has chosen specifically you to discuss climate because you make obviously too many mistakes and ignore too many fundamental textbook knowledge to be really qualified .
You are surely qualified in some other domains where you worked and published but climate dynamics is not one of them .

I will still correct your statements when they will be too obviously wrong but I don’t think that something can come out of this project
Sorry Ed , it was a good idea but the implementation is sofar slightly disappointing .

The fallacy in your argument is your assumption that AGW is the only possible cause of an outcome (like arctic melting) when Nature can also cause the same outcome

You are right with this statement .
But the problem is that this line doesn’t lead very far and Bayes is not helpful at all .
Considered this peer reviewed document : http://www.numberwatch.co.uk/warmlist.htm
Even if the scientific content of each document is unequal , the Bayesian inference is overwhelming .
There simply can’t exist any natural theory explaining all these observations and making all these predictions .
It is so overwhelming that AGW can’t actually be any natural theory , it must be supernatural .

But one also understands how AGW works .
It is called in France the “Madam Irma principle” .
Madam Irma principle says that the more predictions and observations of a theory are vague , the more it will be convincing via Bayesian inference .
The AGW is so incredibly vague that anything fits and if there is something that by miracle wouldn’t fit , it is easy to just add another vague but plausible hypothesis to get a fit again .

Because if one really considers what the AGW is saying it all boils down to a single simple statement – “It will get warmer and the CO2 concentration is the main driver .”
Everything else is then just a consequence of a warming world which doesn’t prove anything about the CO2 hypothesis .

But one doesn’t need to look far to agree that it will indeed get warmer – the Milankovich cycles say so too .
One can even agree that the CO2 will contribute if its concentration changes significantly .

Simulations if one believes them , say that it will continue getting warmer for some 23 000 years .
And after that it will get colder again . And then warmer . Etc .
So it’s actually expected by everybody that it will get warmer .

Is the main driver of Milankovich cycles the CO2 ?
Definitely not .
And here again one doesn’t need a special “theory” .
The CO2 can only act monotonously – more CO2 means more heating which means more CO2 which means etc . Of course logarithmically .
But as we observe cycles , there is something that systematically overrides CO2 .
Or in other words there exists a mechanism which is not CO2 and which is much stronger than the CO2 effect .
This mechanism is not monotonous and systematically overrides the weak CO2 effect to produce the cycles that we observe .
On shorter time scales (decades , centuries) we only see chaotic fluctuations with variable pseudo trends .

This is a general statement in response to the claim that keeps coming up that polar temperatures go up 2 times as fast as global average. The first observation is that Antarctica temperatures have been close to level, with a slight down trend over the measured period.

The Arctic has increased about twice the global rate from 1970 or so until just past 2000. However, it was nearly the same level as present in the late 1930’s. Since the global temperature increased from the 1930’s to the present, this contradicts the claim.

Taking both polar regions into consideration, the statement is clearly falsified.

As has already been noted in comments, here are some, but not all, of your hypothesis’ problems:

1. Historical proxy temperature changes can be explained without invoking CO2 as a driver. You have not shown that CO2 is necessary to explain the historical data.

2. Data show changes in temperature always precede their parallel changes in CO2 by ~800 and 2000 years. Thus CO2 cannot be the primary forcing agent for temperature change at the glacial-interglacial scale as you have assumed.

Then, your dire warning to humanity has many problems, some of which are:

3. The last section of your Fig. 4, which you have used to support your dire warning, is invalid because it compares two entirely different methods of measuring temperature: proxy ice-core data and modern meteorological data.

4. The last section of your Fig. 4, which you have used to support your dire warning, is invalid because it makes use of the Fig. 4 “GHG Forcing” (green line) which has no physical validity and which is itself calculated assuming an invalid CO2 feedback.

Which brings us to the null hypothesis. The proper null hypothesis is:

Global climate changes are presumed to be natural unless and until specific evidence is forthcoming for human causation.

5. Neither you nor anyone has yet provided any such evidence.

6. You have assumed without justification that all the temperature changes you see in your data result one way or another from CO2 changes.

7. The feedbacks you have assumed in your hypothesis are unphysical and, so far, you have not defended them.

8. You can quickly see the invalidity of your hypothesis if you look at formula (1) of @106, which you approved in @108. Your hypothesis has been invalidated by its very formulation.

I agree with your explanation of the logic. But I disagree with your statement:

What I am saying is that the various alternative explanations for observed warming, which run the gamut from “Falsification of Data” to “Increased solar output” are all easily dismissed.

With this, we can embark on reviewing the evidence you have for your statement. Before we do, however, please consider whether we can do this review better and with more focus under the Post “D. CO2 Effects,” since this review seems to lie outside the subject of this Post 6.

“Over the full 420 ka of the Vostok record, CO2 variations lag behind atmospheric temperature changes in the Southern Hemisphere by 1.3$1.0 ka, and lead over global ice-volume variations by 2.7$1.3 ka. However, signi”cant short-term changes in the lag of CO2 relative to temperature, subsequent to Terminations II and III, are also detected.”

And of course, on the dramatically shorter transitions between this interglacial, and the last one back, the better reference (which I have quoted here before is:

Classification of Dansgaard–Oeschger climatic cycles by the application of similitude signal processing

Jordi Solé , Antonio Turiel, Josep Enric Llebot

Physics Letters A 366 (2007) 184–189

“In this work ice-core CO2 time evolution in the period going from 20 to 60 kyr BP [15] has been qualitatively compared to our temperature cycles, according to the class they belong to. It can be observed in Fig. 6 that class A cycles are completely unrelated
to changes in CO2 concentration. We have observed some correlation between B and C cycles and CO2 concentration, but of the opposite sign to the one expected: maxima in atmospheric CO2 concentration tend to correspond to the middle part or the end the cooling period. The role of CO2 in the oscillation phenomena seems to be more related to extend the duration of the cooling phase than to trigger warming. This could explain why cycles no coincident in time with maxima of CO2 (A cycles) rapidly decay back to the cold state.”

5, 6, 7 Although I frequently see expostulations regarding CO2 as the driver, the ice core data, deep ocean drilling program, marr and palynological data have yet to support CO2 as a causative agent for positive temperature excursions in the paleoclimatic record. Numerous hypotheses pervade the literature, from Broecker’s initial float of the THC, to solar irradiance etc., but the fact remains that as of this time, no one really knows.

“you do not realize that WHEN WE USE THE HISTORICAL RECORD OF THE ICE CORES for measuring sensitivities to CO2 the effects of clouds are “automatically” incorporated into the magnitude of sensitivity thereby determined. Now it is true that modelers do have to know all these complex details of clouds when they are predicting the future with computer modes. But Mother Nature is doing that for us when we use the historic record. So if you think I am ignoring the effects of clouds, please think again.”

I cannot resist.

First, when the concept of “slow feedback” is invoked, and more warming forces more ocean outgassing and more CO2 in a feedback loop, the entire concept of “sensitivity” becomes meaningless, because the CO2 is no longer independent variable, it is a coupled variable (aka “emergent” variable, in climatardant speak), it emerges out of control of experimenter. Thus, the whole concept of “slow sensitivity” is inherently flawed.

Second, while the Mother Nature does reflect all changes in all variables (which includes clouds) in the projection of climate state onto single borehole in the middle of Antarctic, the Mother Nature stays in deep silence and is not helping when someone tries to analyze and separate an effect of one variable (CO2) from compound effect of all other, much more potent variables.

Tom Curtis asserted in #161:
“The change in forcing due to a 10% increase in cloud cover is therefore, unlikely to excede 1.5w/m^2 globally averaged”

Dear Tom, your assertion “contains an error of fact”, as you eloquently expressed yourself. Your speculations have no factual ground.

As you might be aware, the outgoing irradiance and “radiative forcings” are delicate things, and require certain “radiation codes” to be run in conjunction with spectral information of air mixture, its dependence on pressure, and overall vertical temperature profile of atmosphere. This is usually done by means of nontrivial models and corresponding databases. If you have heard of such fine scientists as David Archer and Ray Pierrehumbert, both of University of Chicago and proud founders of RealCimate, you may want to examine their raidative-convective model based on MODTRAN spectral database,http://geoflop.uchicago.edu/forecast/docs/Projects/full_spectrum.html

Please do yourself a favor and follow these simple steps:

(A) Run their model with defaults. The model will calculate the equilibrium surface temperature of 289.1K

As I said I will limit myself now just to correcting wrong statements .

Eric said :

“Of course, clouds, are VERY important in affecting climate. However, what now is becoming increasingly clear to me is that you do not realize that WHEN WE USE THE HISTORICAL RECORD OF THE ICE CORES for measuring sensitivities to CO2 the effects of clouds are “automatically” incorporated into the magnitude of sensitivity thereby determined. ”

This statement is amusing .
Let’s suppose that the temperature T at the South pole at some time t is given by a function T = F(c,k,o) where :
c is the CO2 concentration , k is the cloudiness at the South Pole and o is the ozone concentration above the South Pole .
Just to avoid red herrings that Tom Curtis is fond of catching , t is any time . It might be 65 My ago or 400 000 years ago . It applies on any chart you show .

Trivially we have dT = DF/Dc .dc + DF/Dk . dk + DF/Do.do where D is the partial derivative .
Measuring dT/dc means to measure : DF/Dc + DF/Dk . dk/dc + DF/Do.do/dc .
Now you decide to call dT/dc “CO2 sensibility” .
Why not , you may call it fruugh and nobody will care .
But you then proceed to say that this same parameter is dT/dc = S(c) where S is some function of c or even a constant !

OK that means then that DF/Dc + DF/Dk . dk/dc + DF/Do.do/dc = S(c)
So as all the terms must be functions of c (or constants !) unless all terms in o and k magically cancel we have F = a(c) + constant .
In other words the cloudiness and the ozon concentration or anything else for that matter have no impact on T .
This contradicts the fact that T depends obviously on k , as you say clouds, are VERY important in affecting climate .
Actually what you did was confusing dT/dc and DT/Dc but why should we bother , we’re doing “climate science” after all .

But the main problem of using AGW as science is that there’s really no convincing – e.g. five-sigma – evidence supporting the key propositions which is likely to be because they are not “universally” right.
There’s so much data in the world that one could construct 5-sigma “proofs” of the key statements if this were possible.
While 5-sigma proofs lead to a “substantially higher certainty”, they’re not much harder to be found.
You need just 5 times more data to find a 5-sigma proof than a 2-sigma proof – assuming that your conjecture is right.
If you can’t get to 5-sigma proofs for a long time, it’s probably because all the 2-sigma signals are noise.

So no such 5-sigma “proof” exists in the literature. If there existed a paper that actually contained solid evidence for the key theses of the AGW orthodoxy, the proponents of the carbon regulation wouldn’t hesitate before they would show us such a paper.
Clearly, the paper that would be analogous to “Zur Elektrodynamik bewegter Körper” which showed that special relativity was true simply doesn’t exist.

In conclusion – what does the geological record tell us about the potential effect of continued emissions of CO2?

Over at least the last 200 million years the fossil and sedimentary record shows that the Earth has undergone many fluctuations in climate, from warmer than the present climate to much colder, on many different timescales. Several warming events can be associated with increases in the ‘greenhouse gas’ CO2. There is evidence for sudden major injections of carbon to the atmosphere occurring at 55, 120 and 183 million years ago, perhaps from the sudden breakdown of methane hydrates beneath the seabed. At those times the associated warming would have increased the evaporation of water vapour from the ocean, making CO2 the trigger rather than the sole agent for change. During the Ice Age of the past two and a half million years or so, periodic warming of the Earth through changes in its position in relation to the sun also heated the oceans, releasing both CO2 and water vapour, which amplified the ongoing warming into warm interglacial periods. That process was magnified by the melting of sea ice and land ice, darkening the Earth’s surface and reducing the reflection of the sun’s energy back into space.

Is there any particular reason why 5 sigma should be the routine standard for climate science? I’m pretty sure that meteorologists use a lot less for their other work.

Yes . Because if there is not a 5 sigma proof (or better) despite searching for 30 years , then low sigma signals are almost certainly just noise .
In hep there is even a rule that 90% of papers based on 2 sigma signals will turn out as being garbage .
This is an expected routine standard for any new theory , not only climate science .

I don’t see what metorology has to do with this matter .
Meteorology is just Navier Stokes and conservation laws .
Obviously the conservation laws and N-S which are theories (while meteorology is not) are proven at much much better level than 5 sigma .

I don’t know about the math you provided, but whatever the math is that accounts for clouds and everything else that is coupled to temperature which is coupled to CO2, my point is that Mother Nature acts in accordance with that correct, but unknown math and then provides us with answers in the ice core records.

This is just too bad . Because if we don’t have even mathematics as a common language then it will indeed be difficult to communicate .

one detailed comment concerning your math: dT/dc is not how we define “CO2 sensibility”, as you might know – I just want to be sure because of the confusion others have had over this point

Yes I know that it is dT / dF . But as no chart you showed displays dF and it is indeed unknown (clouds , remember ?) , one usually writes dT/dF = dT/dc . dc/dF .
dT /dc can be read on the chart and dc/dF is estimated .
I made a shortcut to dT/dc indeed and called it “climate sensitivity” because that’s what it actually is and it is the only parameter available on charts .
But you are right , it is not the conventional definition .
The rest of the maths is of course correct whatever the definition of climate sensibility is .

Last comment .
I have already written that you really fit badly among the climate “scientists” and must repeat it .
You miss the characteristical arrogance an you are able to say “I don’t know” .
You are also able to listen to contradicting arguments what a true climate”scientist” would never do – just visit Tamino’s or RC to see how these people behave .
I must say that it makes the discussion possible even if I don’t agree with much of what you wrote .

Here’s how I interpret these charts . It is mostly qualitative but will do .

1) The system is in a chaotic pseudo periodical regime (obvious on the chart)

2) We know of a relevant chaotic pseudo periodical regime – orbital parameters . Of course this limits us only to the recent past (say a couple of millions years) because beyond that , the orbital parameters are per definition unknown .
There could have been another planet in the Solar System in the far past for all we know and it has been in the meantime ejected . Always for the same reason – the system is chaotic . This makes considerations about orbital parameters in the far past just wishful thinking .

3) There is a mechanism connected to orbital parameters (obliquity and excentricity are the most probable suspects) which chaotically modulates the dynamics of the Earth system on intermediate time scales (say centuries and millenaries) . From here on I talk only about the recent past for the reason mentionned in 2)

4) This mechanism is dominating the dynamics at the relevant time scales . It is clearly cyclical (quasi periodic) what one expects from a chaotic behaviour . If there are any other mechanisms and there are many , they are much weaker . Especially monotonous mechanisms (e.g that are aperiodic) are always overriden because else one could not explain why the curves have maxima and minima .

5) If one considers CO2 (or any other dissolved gas) , it will always be correlated to the temperature . That’s just Henry’s law . So what we see on the charts is just Henry’s law .

6) CO2 is one of the multitude of weak parameters that also impact temperatures in a very simple way . But the CO2 mechanism , the GHE , is aperiodical . It is unable to drive cycles . As exposed in 4 and as the charts show , it has always been overidden – the T derivatives always change sign at some point . Therefore while CO2 plays a role , this role is minor as compared to the real orbital drivers .

7) If one goes then to much smaller time scales (decades) , then CO2 is obviously irrelevant . What takes the lead here is the atmospheric and oceanic chaos coming from Navier Stokes . The aperiodic CO2 role is permanently overidden by strongly coupled oceanic chaotic cycles (ENSO , PDO , AMO etc , see Tsonis) . The Sun cycles (solar and magnetic) may also play a role but it’s not sure (yet) how strong .

Dr. Eric @148,
Even now climatologists admit that the cause and effect of cloud variation is NOT well understood. Strange theories such as Solar magnetic field variation (associated with sun spot frequency?) changing cosmic ray intensity, and resulting in cloud variation, are being given serious consideration. There are other theories for distant past, including significant solar intensity variation. The point is that if we do not know anything except that when it gets hotter, the CO2 and even methane goes up, this does not support the CO2 as cause of most of the heating, and certainly says nothing about positive feedback. I will admit that if a critical temperature is reached that a methane eruption of large size could cause a temperature surge (PETM), but those are isolated events, and excess methane has a relative short life in the atmosphere. There are also melt water surges and other isolated events that have large effects. In addition, plate motion is approximately known going back, but not exactly, and land location is a big driver. I consider the deriving of sensitivity based on shown data as highly speculative, and probably wrong.

@ 31 on GHG Effects continued and moved over here to the Last Age Ages as Ed requested

Ed,

Please see my responses below shown after each of your 8 points:

1. Historical proxy temperature changes can be explained without invoking CO2 as a driver. You have not shown that CO2 is necessary to explain the historical data.

My response: I can not respond to your first sentence, of course, until I have seen your evidence (note that proof is not necessary) for it. Concerning your second sentence: a agree – I have not yet shown that. But then we are just getting started aren’t we. When we are all on the same page with respect to understanding what is being said in the literature and with respect to important terms and definitions, we will hopefully be able to has a decent discussion on this point pretty soon.

2. Data show changes in temperature always precede their parallel changes in CO2 by ~800 and 2000 years. Thus CO2 cannot be the primary forcing agent for temperature change at the glacial-interglacial scale as you have assumed.

You should look at Thomas Gregory excellent comment this morning in Post #6. He understood what I am said and summarizes it accurately. CO2 certainly does not necessarily or even ever initiate a change in climate direction. After a delay of a few hundred years, however, CO2 follows the new direction and from then on – for many subsequent thousands of year contributes greatly to the subsequent large temperature changes.

Then, your dire warning to humanity has many problems, some of which are:

3. The last section of your Fig. 4, which you have used to support your dire warning, is invalid because it compares two entirely different methods of measuring temperature: proxy ice-core data and modern meteorological data.

Response: Two methods of measurement are better than one as would be ten if we could find them. In addition, of course, some methods only worked during different periods. All should be used and assessed however.

4. The last section of your Fig. 4, which you have used to support your dire warning, is invalid because it makes use of the Fig. 4 “GHG Forcing” (green line) which has no physical validity and which is itself calculated assuming an invalid CO2 feedback.

First, are you possibly overusing the word “dire”. Just the word “warning” might be fine with just a few “dires” throught in occassionally. GHG Forcing does have a physical validity and is used throughout the literature and in the Hansen et al paper under consideration. I am certainly not willing to accept your statement that CO2 feedback is invalid. The evidence to the contrary is so strong that it rarely requires much justification. But if you require a revisit to such basic notions, we will go there in due time.

Which brings us to the null hypothesis. The proper null hypothesis is:

Global climate changes are presumed to be natural unless and until specific evidence is forthcoming for human causation.

5. Neither you nor anyone has yet provided any such evidence.

In a upcoming blog we will be getting into the Age of Man in which such evidence will be extensively discussed. What’s called the Keeling Curve for example, and many other indicators of human causation will be presented. If you are not familiar with the Keeling curves and the associated measurements of that nature being made throughout the world, you might considered reading up about it before we get there – but we will indeed get there.

6. You have assumed without justification that all the temperature changes you see in your data result one way or another from CO2 changes.

This statement is false, I have made to such assumption. Other factors also contribute to temperature changes, as we all know very well.

7. The feedbacks you have assumed in your hypothesis are unphysical and, so far, you have not defended them.

I can not respond because I don’t know what you mean by the word “unphysical”. And I am not asking you to go anal retentive here in coming up with an exact definition. Just tell me what you mean by this word in this case or try another word.

8. You can quickly see the invalidity of your hypothesis if you look at formula (1) of @106, which you approved in @108. Your hypothesis has been invalidated by its very formulation.

Sorry, but I can’t actually see the “invalidity” you describe, so I don’t can not yet respond. And just to help me understand what you are referring to, please expand describe the evidence the invalidity that you say exists here.

What causes the interglacials:
The argument is proposed that something (orbital tilt variations?) triggers the start of a interglacial period by selectively melting sea ice near the poles and possibly decreasing snow coverage elsewhere. These cause decreased albedo, and result in some average planetary warming. The warming slowly releases some CO2, mainly from the oceans, with a lag of several hundred years. The CO2 then raises the temperature more, which causes increased water vapor concentration to act like a positive feedback and forces the temperature higher yet until the process self limits.

There is a flaw in that argument. If we assume the first part about the initial trigger for the interglacial being valid, this was assumed to result in some average planetary warming. Why would the warming due to the initial trigger not cause increased water vapor concentration, which would act like a positive feedback and force the temperature higher yet until the process self limits? While it is likely that the added CO2 does add some to this process, why is it considered the main forcer? It appears the feedback is not due to any special property of the CO2, but is caused by a temperature increase causing more water vapor.

Yes, water vapor changes will always provide “very, very, very fast feedback to all temperature changes, large and tiny. Initially while the initial change of temperature direction is very small, due to orbital changes or other factors, a small instantaneous water vapor feedback will certainly be there – well before the CO2 feedback kicks in a few hundred years later – and that water vapor feedback will initially provide assistance to those initial orbital or whatever changes.

I agree your points must be discussed. I will comment below but first I would like to emphasize that the way we ultimately resolve your points must be the result of a cooperative discussion of all the scientific minds participating in Climate Clash. (This is not a matter that will be decided by an Administrative decision.)

Therefore, I am here speaking with my own viewpoint as a scientist albeit with the bias of being on the defense. Using your numbered points:

1. Models embody hypotheses which have resulted from studies of data. Data alone prove nothing. Models or hypotheses prove nothing. The only way to test a model or hypothesis is by comparing a prediction with data that has not already been incorporated into the model or hypothesis.

2. From our previous discussions, we both agree that a hypothesis can never be “proved” but with a track record of good predictions, a hypothesis will be elevated in credibility. On the flip side, a bad prediction means the hypothesis is wrong. The only way to respond to an incorrect prediction is to look for a better hypothesis.

All data comes from measurements that have errors and predictions themselves have errors. Therefore, all tests of predictions against data will have a statistical result. Sometimes, if we are lucky, the effect will be so large and the margin of error so small that we don’t need fancy statistics to see the answer. I think you agree with this too.

3. This point will produce the most discussion. Your suggestion is whether one model of a complex system can be tested in the absence of an alternative model.

Assuming we have two models, if one model fails this cannot prove the competing model succeeds. Both may fail. If one model results with a 30% probability of being true and the other with 25% probability of being true, I would conclude they both fail and the margin of difference is not sufficient to declare the 30% model the winner.

In the case of this AGW debate, the default hypothesis on the defense side is that nature is responsible for whatever prediction we are testing. The more precise statement of this is the null hypothesis:

Global climate changes are presumed to be natural unless and until specific evidence is forthcoming for human causation.

Therefore, my answer to your question is that the null hypothesis is your competing alternative hypothesis.

This null hypothesis for AGW is an exact parallel to the accepted null hypothesis for testing cloud seeding hypotheses (also a complex system).

A cloud seeding hypothesis is tested by whether the “added cause” produces a statistically significant difference compared to what the cloud system “would have done” lacking the added cause. By this means, cloud seeding hypotheses have been tested in the absence of having a complete understanding of the complex processes inside a cloud system. I think AGW must follow this method.

3A. This is not to say that proposing an alternative model is not an option for the defense. For example, many comments back, I asked whether you would entertain an alternative model – to your long-term model that makes CO2 an important cause – with an alternate model that makes Temperature the more important cause.

Suppose you had accepted this as a competing model. Suppose further we were somehow so smart that we could find a way to truly test this alternative model against your original model. Here are two possible outcomes of such a test:

(a) Your model makes better predictions. In this case the alternative model fails. Your model becomes the reigning model. But until your model overcomes the null hypothesis it has not proven itself to be “true” and cannot be used to predict AGW effects.

(b) The alternative model makes better predictions. In this case, your model fails and the alternative model becomes the reigning model. If this alternative model predicts no AGW problem then the defense will have won.

If the defense wins in any phase, it means only that the prosecution has lost that phase. The prosecution always has the option to propose another hypothesis in phase two.

Dr. Eric,
As most here know, human activity (burning fossil and other fuels, manufacturing cement, land use, and building large amounts of roads and buildings) do affect some local and even some regional climates. They certainly also affect the global climate. The issue is not if, but how much. If you claim “winning” as showing some effect, you are making the wrong point. The winning or losing point is predicated on two points. First, that it is CO2 causing the problems, and second, that it is a significant effect with dangerous implications (flooding, storms, drought, dangerous peak temperatures). Since this is a subjective call (how much is called bad), this will not allow a clear winner. However, if the scientific evidence supports that the likely hood is the temperature will rise by >2 C by 2100 DUE to CO2 increase, then I would call you winner, even if that rise is not shown to be associated with other major problems. Otherwise you lose. Since we will not be here 2100, we have to use available data and trends, and supportable logical analysis.

My view of the philosophy of science and the scientific method is exactly as I have expressed in my @188.

I have no burden to create a “natural” model. Nature itself is the natural model, and nature is a far better model than I can create.

The whole basis of the AGW hypothesis is that we humans are doing something that changes nature. The AGW hypothesis compares itself with nature, not with another model. If you cannot show our CO2 changes nature then the AGW hypothesis will fail.

As prosecutor, you have the burden to show that human CO2 is causing a significant change in nature. AGW is truly a weather modification experiment and it must be subject to the very well developed methods for testing weather modification hypotheses. The modification cause is to put human CO2 of a defined amount and rate into our atmosphere. You must show that the modification effect changes nature a “significant” amount.

Using the example again of cloud seeding. For example, the prosecution hypothesis is that inserting silver iodide, in a certain amount, at a certain rate, at a certain time in the lifetime of a cloud system, in certain weather conditions, will cause the cloud system to produce more precipitation than if the cloud system were left alone. That is the prediction of the hypothesis. Now the prediction must be tested against new data.

The prosecution must demonstrate the cause produces a measurable, statistically significant effect as predicted. When this is done successfully, then the null hypothesis has been invalidated and the hypothesis has been successful. That is the only way to demonstrate there is any validity at all to the AGW hypothesis.

This test of a hypothesis is carried out without a need, or even the desire, for an alternative model. In fact, using an alternative model complicates the experiment. The prosecution must show that the modification effect of CO2 changes what nature would have done in the absence of the modification.

I cannot accept your statement:

I hope you aren’t suggesting that your “natural” model will not require careful examination here because of some phrase called “null hypothesis”. Whatever that term mean might mean in any given application, it has no place here.

The null hypothesis is the only accepted scientific way to test any hypothesis. It not only has a place here, it is absolutely required to have a place here. You must clearly understand what the null hypothesis means. Without using it, we are not even talking about science.

@192,
Obviously you do not understand the epistemological meaning of “null hypothesis”. In case of Darvin’s Theory of Evolution, the null hypothesis is “world was created as it is, nothing has ever changed in the past 6000 years as we know it from scriptures”. The Theory of Evolution proves that this null hypothesis is wrong and explains all collection of known facts recorded by Mother Nature. More, it makes verifiable predictions, and has practical use.
– http://www.talkorigins.org/indexcc/CA/CA210.html

that there is a plausible explanation of ice ages without any CO2 “forcing”. Their work shows that there is enough forcing and enough complexity in climate subsystems to make ice ages happen. What is missing in their analysis is a fact that any system of climate complexity does not have to have any drivers to generate wild quasi-periodic excursions.

I am sure you have heard about a thing called “Nonlinear Dynamics”, but I am equally sure you have no clue what does it really mean. For your information, there are real people that are working on real problems of climate, except that it does not pay much from green funds, so they are unpopular. Here is one example:

Unfortunately, classes on environmental studies do not cover this kind of mathematics, so all this might look as a gobbledygook to people of your ilk and other chemical professors. Two years of post-graduate studies might bring you up to date, but only if you find a right University, maybe somewhere in Mexico.

If you are a real scientist and have a real desire to find scientific truth, take an effort to understand the real science behind climate complexity. I am willing to apologize if you show any signs of learning effort.

@180 & 181,
The Human contribution to CO2 is likely about 100 ppm not 16 (which gives 1/10,000 of the atmosphere increase). This along with all feedbacks has probably caused a maximum temperature rise of about 0.3 C (the rest up to 1940 is claimed to be natural recovery from the LIA). Most of the warming is NOT due to higher maximum temperatures, but less cold minimum temperatures at night, and at higher latitudes. i.e., it has gotten more comfortable. Also lower delta T means LESS storms (they are driven by larger delta T). So 180 is basically closer than 181 seems to think except for the CO2 number.

@198 Dr. Eric,
Why do you keep repeating the Keeling Curve issue. I think we all know the CO2 has gone up and a large part of the increase is likely due to human activity. The correlation of the CO2 curve to warming is a poor correlation. Better correlation are found with sunspot number, with several ocean current cycles, and some others (including known unrelated subjects), but correlation does not prove causation (I hate that phrase, but it is true), and a bad correlation proves nothing anyway.

@ 198, it looks like cognitive abilities of some provincial professors are heavily distorted. In topic 1 @ 38 I have presented an evidence from a lecture of prominent climatologist Corinne Le Quere that “CO2 EXCESS” is not an easy function for Mother Nature to compute, so my thesis was quite substantiated. I also explained that spot concentration is the same kind of “intensive variable” as temperature, so the limited ensemble of “Keeling Curves” might not be the “most important” thing in the world.

Apparently some professors of chemistry should start looking outside their usual mixtures that are always in thermodynamic equilibrium, and should be studying some elements of non-equilibrium processes before embarking on such a system as climate.
But I understand that I would need to repeat my explanations few more times, as our previous encounter with “polar amplification” shows, which took 4 (four!!!) attempts. Still waiting for your evaluation of merits of “polar amplification”, see your promise (6 @ 120) to be not a penguin following their leader.

I’ve read through the first paper you cite and don’t see that it negates Dr. Eric’s presentation at all. In fact based on my readings here and at other places from people who have studied this issue in much more detail than I it seems to be in complete agreement with it. Once again there is an initial forcing and that could indeed be the Milankovitch cycles in many cases. After that initial forcing there are a series of feedbacks that contribute to either the warming or the cooling. I just finished reading another post here from another climate scientist and they describe this exact same process.

Here is a quote from Dr. Jeff Severinghaus of the Scripps Institution of Oceanography from the link shown above: “But do not make the mistake of assuming that these warmings and coolings must have a single cause. It is well known that multiple factors are involved, including the change in planetary albedo, change in nitrous oxide concentration, change in methane concentration, and change in CO2 concentration.”

Way back in “3. Are we at an Impasse?” you said you accepted the scientific method as I described it. Now you say you do not. You ask me:

Do you not understand where science has been for the last many centuries?

Such a question gets us nowhere. And you say in @189:

I hope you aren’t suggesting that your “natural” model will not require careful examination here because of some phrase called “null hypothesis”. Whatever that term mean might mean in any given application, it has no place here.

You write in your @192:

Are you beginning to understand this central point? If you can’t develop a model for the natural world, how do you have any idea at all of what cause and effect relationships have been in the past and should be in the future?

You are telling all the meteorologists and statisticians who developed the proven methods to test hypotheses in weather modification by using a null hypothesis, that they did not understand “the last many centuries” of the scientific method.

You are telling Richard Feynman, who nowhere in his description of the scientific method requires the invalidator of a hypothesis to develop a model of nature in order to reject a hypothesis, that he did not understand “the last many centuries” of the scientific method.

You are telling John Kemeny, the special assistant under Albert Einstein, who’s book, “A Philosopher Looks at Science” dedicated “To Albert Einstein,” nowhere requires the invalidator of a hypothesis to develop a model of nature in order to reject a hypothesis, that he did not understand “the last many centuries” of the scientific method.

I digress here to a review of Kemeny’s book that gives a sense of what I experienced by studying under John Kemeny at Dartmouth College, as I reminisced in 3@14:

I read this book when I was seventeen years old, battling the demons of art and science, wondering if there was a connection between both those seemingly incompatible worlds. The book confirmed my decision to go to Dartmouth, where, as it happened, I spent four years studying in the math building, even though I was a liberal arts major.

I simply liked the vibe and John Kemeny’s presence. He was there, hovering about, checking on everybody and making the math department at the college the best in the country, building the first computer center, and with Thomas Kurtz, inventing for all of us the BASIC programming language.

One time when he encountered me he asked what I was doing reading “Lolita,” one of the books required in my American literature course, in *his* math building. I said, “Well, I want to be a writer and a computer scientist, to master the language of Nabokov and the thinking of Kemeny. I want to stand on the shoulders of giants.”

Kemeny smiled and shook his head, as if to say, “You’ve got your work cut out for you, young man.” Which was true: it took me about one hundred years to do what I’m doing now: writing software code and technical documentation at Apple Inc and, nights and weekends, writing one novel after another, always experimenting with language, voice and imagery.

Indeed, my prediction way back in “3. Are we at an Impasse?” has come true. From my viewpoint, the fundamental reason why you and other university scientists support AGW is because you do not properly use the scientific method, including the role of the null hypothesis in rejecting an alternative hypothesis like the AGW hypothesis.

What good would it do for me to follow through with my @158 and @164 claim that your hypothesis is invalid?

If I showed you how your hypothesis is clearly invalid … you would not accept my negation of your hypothesis. You would claim in your faulty reasoning that I must first propose and defend my own model of nature.

Your requirement, if applied to a criminal trial, would require the defense to provide a complete alternative to the prosecution’s hypothesis, rather than simply proving his client was in New York at the time the crime occurred in San Francisco. You would not let the defendant off the hook until the defense could provide an alternative hypothesis about how the crime occurred in San Francisco. Such a requirement would be absurd.

In your rejection of the null hypothesis, you disagree with Wikipedia:

The practice of science involves formulating and testing hypotheses, assertions that are falsifiable using a test of observed data. The null hypothesis typically proposes a general or default position … It is typically paired with a second hypothesis, the alternative hypothesis (this is the AGW hypothesis – Ed), which asserts a particular relationship between the phenomena.

Hypothesis testing works by collecting data and measuring how probable the data are, assuming the null hypothesis is true.

In scientific and medical research, null hypotheses play a major role in testing the significance of differences in treatment and control groups.

I don’t see what we can accomplish in debating AGW when you have an unsupportable interpretation of the scientific method. Science hangs on the philosophy of science and you have rejected the philosophy of science.

Rather than claiming I don’t “understand” the scientific method, you must demonstrate your above assertions are true, which so far you have not done.

Do you have philosophical and scientific references showing that all the philosophers and scientists I mentioned above were wrong?

Was our whole debate in “3. Are we at an Impasse?” to no avail. You accepted our debate terms then. Are your now looking for a way to wiggle out?

@ 203,
I do not know for sure that the 100 ppm increase is human caused, but reasonable data and arguments indicate it is so. The basic argument is that even though only a few % (4%?) is due to human activity, the removal vs input balance was slightly offset, and the net effect was that a small amount of CO2 started to accumulate. The excess started slow, but has reached an addition of about 2 ppm per year. Accumulating over 150 years, the excess reached a significant level. Keep in mind that I am a skeptic, and do not think the increase is bad. In fact I think it has helped food production. I also do not think it will cause a significant temperature increase. I try to be fair on the facts rather than resisting any that either side makes.

@ 203,
Think of a bucket with a small hole in the bottom and a running stream of water. The water level will rise until the in and out flows are matched. If a much smaller additional flow is now introduced, and in fact the much smaller flow is slowly continually increasing, the water level will slowly rise. If the size of the exit hole slightly decreases with time, the difference can be even more. The saturation of sea water CO2 level and limited plant growth removal are posited to be the restriction. I don’t know how valid the details are, but it seems plausible, so I accept it for now.

Dr. Ed, thank you for fixing the log-in feature! I’ve been wanting to comment several times but have found myself unable. Fortunately my points were subsequently well-made by others.

I’m gravely concerned by the present situation. If the case cannot be prosecuted fully in accordance with the scientific method then it is impossible to have confidence in its findings, or even conceive of a format in which the case can proceed. The null hypothesis is core to the procedure and the fact that it appears to be not only an unwelcome constraint but an alien concept to the prosecution is, to say the least, disconcerting. This is Scientific Method 101.

I’m bound to ask if this disregard of the scientific method is peculiar to Dr Eric or if this is symptomatic of proponents of climate science hypotheses. Is it perhaps a marker of a systemic failing in fledgeling Environmental Sciences? I have glibly proposed in the past that untenable and alarming hypotheses promoted from within the field of Climate Science are the net result of “bad parenting” – something perhaps in part touched on by Dr Curry in here recent Positive Feedback Loop essays. Given Dr Eric’s apparent ignorance, and blatant dismissal, of the null hypothesis, I now wonder if I should have been so glib.

I have referred to the Keeling curve so far only with Al. The reason is in an early post suggested that the Keeling Curve is meaningless and will be irrelevant to future discussions of the Age of Man (if we ever get there). Then I told him about the significance of the KC and dozens of other monitoring stations and told him to learn a bit about them. So that’s why, when Al has subsequently weighed in, I have reminded him of the Keeling Curve.

Regarding @217: “The BS I was clearly referring to was that offered by Al in his dismissal of the Keeling Curve.”

Note to “jury”: apparently our AGW professor has no issues with stretching the truth (as all AGW people do with theories, proxies, and data), but has severe problems with logic. The issue in question here is about dubious statement of Dr.Eric that “our Co2 will stay essentially forever”, see 1@00. He was confronted with some facts from observations of perturbations of climate from volcano eruptions.

Let the record show that in 1@26 Dr.Eric has expressed his concern that he “can’t think of a quick mechanism of CO2 removal”. In 1@28 I have presented estimations (all based on field observations of ABL and CO2 near-ground fluctuations) that the entire atmospheric carbon can be hypothetically consumed in a matter of 5 weeks.

The record 1@31 also shows that Dr.Eric believes that it is the EXCESS of CO2 that is the physical driver of CO2 dynamics. What he failed to understand is that the actual processes (sources and sinks) are operating nearly independently, such that the EXCESS is only a virtual account of their difference.

In 1@34 I attempted to explain multitude of flaws in his belief.

Instead of trying to comprehend the distinction or debunk my arguments, Dr.Eric resorted to snide remarks about my brain, waco, talking to dogs, etc, and essentially repeated his assertion that it is the EXCESS (accumulating in the skies) that is of most importance, by referring to “Keeling Curve”.

As a favor to other readers and members of this jury, I submitted evidences that exhibit substantial variations in Keeling Curves, and that the EXCESS is a highly variable and uncertain function in time.

Record 1 @ 39 shows that Dr.Eric did not make any effort to analyze the issue, accused me of ignorance in Keeling Curve for the second time, and put forth some standard slogans from AGW theory that all curves “are nearly identical”, and emissions in NH “are slightly greater”, as somehow it reflects the actual physics of CO2 sources and sinks.

In 1 @ 39 Dr.Eric declared that the Keeling Curve is the “central source of AGW information”. I obviously disagree with this opinion, so do observations of characteristic decay of perturbations from volcano eruptions.

For the record, allow me to reiterate my point. The point is that the Keeling Curve is an account for only one part of the actual CO2 processes that are going on the surface and enter the immediate layer called “Atmospheric Boundary Layer”. The observation in the “bulk” unfolds only a small sink across the upper boundary of this layer, and tells nearly nothing regarding dynamics of CO2 sources and sinks. Given the admitted “significant scientific uncertainty” in actual CO2 processes (as mentioned in 1 @ 32 by John Droz), the importance of “Keeling Curve” is therefore vastly exaggerated.

If this line of reasoning looks as BS to Dr. Eric, then it is up to the jury to decide.

The only purpose of KC is to maintain the scare image of increasing “CO2 radiative forcing”, which is also a dubious and highly overrated concept.

@ 212,
I and several other skeptics continually correct errors and misstatements on both sides of blog positions and comments. There are less desirable comments from both camps. However, I have gone to CAGW supporting blogs, and I assure the comments from skeptics, even the valid scientific questioning ones, are either cut out or responded with nasty comments most of the time (there are exceptions such as ScienceofDoom). On the other hand, while there are bad comments on skeptics blogs, they tend to all be allowed ON BOTH SIDES of the issue, and in general the nasty comments are fewer. It appears this is a highly polarized issue, and all of this is not unexpected. However, each of us need to be as fair and respectful as possible to have a chance to resolve the issues.

@ 228,
First, I went to RC early in the process. Don’t you tell me these are nice guys being picked on. They are very nasty people, and were from the start (I actually went into the debate accepting CAGW and wanted to clear up some questions and was blown off. When I made a deeper study of the issue, it became clear that a mistake was being made). Second, anyone putting out a blog should expect questions and even negative comments. They didn’t have to blog, they chose to. Third, I followed Anthony and I don’t agree with every position he has. If I see a clear questionable item I question it, and so do others. That is how a blog should work. As to Christopher Monckton, I think he does a remarkable job with the resources he has. He is wrong occasionally, but more often than not he is correct. He list dozens of points and a couple were shown to be mistaken, and several are in dispute. So what. If he was to blog, I would question where I disagree. He gives position talks, so I can’t directly interact. The same as Gore, except Gore is almost totally wrong on many of his points, and Gore doesn’t even debate the issue as Christopher Monckton does. I don’t remember many CAGW supporters making negative comments on Gore’s mistakes.

The skeptics (and some AGW and even CAGW supporters) are not consistent because they are independent individuals and groups, with a wide range of positions. Some are funded, but most are not, and are doing what they do because they, like me, see a very bad mistake being made in both facts and priorities.

@ 228,
I deplore the bad treatment of scientists because of any belief. However, long before climate gate, the people you say are being treated bad were treating any who disagreed with then very bad, and even pushed having some fired, or at the least, not being published or not getting legally requested information. Some politicians, news media and even some scientists, called skeptics criminal or worse. After climate gate the worm turned. Don’t you think it was the backlash from bad actions that caused bad reactions?

Climatards don’t like to mention these numbers. They used to be on Wikipedia, but later were edited out by enthusiasts.

You would need to download the generated time series, and do averaging by yourself.
For example, in the past 50,000 years the min of insolation was 341.3596 W/m2
and max was 341.7383 W/m2 (assuming the solar constant is constant). This makes the difference of 0.38W/m2.

Every child in climatology should know these numbers. But all this is nonsense.

@237,
It is interesting you found my first entry in RC in 2009. I don’t remember my first entry, but I posted several at earlier times and they were not allowed. They were all polite and questioning, but stated my disagreement on what was said, and they were not accepted and shown. I do not make snide or nasty comments except as direct response to one first directed at me.

@237, Tom,
You really ought to read the comments on the present RC. There were entries by two different people that were treated with the maximum disrespect. One made some statements, but indicated he wanted to discuss them. He was treated very bad. The other gave his opinion, and a reply should have been made to explain his information. He was treated even worse. Actually those two were allowed to publish their comments. I was not published in the comments in earlier times unless it was a trivial point that they thought they could easily refute. That is how they have worked from the beginning.

“No, Gavin, it is not an arbitrary metrics, and not off topic since cloud cover is an important part of a good climate model. How important? Look at the full-spectrum model of atmosphere offered here:
forecast.uchicago.edu/Projects/full_spectrum.html
You can see that 1.4% change in low cloud cover negates the whole effect of CO2 doubling. Clearly, changes in process of cloud formation are two orders of magnitude more important than changes in CO2. Do you have paleorecords of cloud cover 100,000 years ago, with about 1% accuracy?”

[Response: Of course not. Frankly, we don’t even have that for today’s climate. Thus we can know nothing. Brilliant. I’ll just pack up and go home then….. Seriously though, the issue is to always take the information that you do have and do your best to make sense out of it, not to sit around wishing for perfection. I think there is useful information in paleo-records and I have written many papers exploiting it – it could be done better of course, but it is pretty amusing to hear over and over that something can’t possibly be done when it already is being. You want examples? Try Otto-Bliesner et al (Science, 2006), or Legrande et al (PNAS, 2006) or Schneider von Deimling et al (2005). – gavin]
=== === ===

Please note the same philosophy as it was expressed here by Dr.Eric and Tom Curtis – do your best even if you have to ignore effects orders of magnitude bigger assuming them as constant, even if you would submit evidence that it is not true, right in their faces. Response of Tom Curtis to my 6 @ 165 was educational.

@ 250,
There has not been enough substantial data and analysis yet put in and discussed by Ed and Eric to vote on the case yet. Most of the material and discussion has been preliminary background, and a lot of bickering. Voting to see who has a majority at this level is exactly what the pro CAGW people did to shut down the debate, so let us not use that tactic.

When a reasonable list of falsifiable points are made and attempted to be defended or falsified, then we can discuss who won the debate. We do need to keep in mind that Ed does not need an alternate hypothesis, since the debate is on the validity of the CAGW hypothesis, and a hypothesis can be shown to be invalid with just one falsification of a CRITICAL claim (non critical claims can be adjusted if shown wrong).

@ 253,
Sorry but I have to respond to some of this. The sea level increases from melting land ice, and thermal expansion of sea water. The deep ocean was made very cold during the last glacial period ending about 11,000 years ago. Since then the warmer interglacial has continually contributed to fast surface water warming, and slow deep water warming, as well as the huge initial land glacier melt. Once most large land glaciers melted, rise slowed, but has continued over the whole Holocene, with some slowing and speed up with long period variations such as the MWP and LIA, and now the present warming. The average rise over the last several thousand years has been a bit over 1 mm/y, but has varied from 0 to 4 mm/y. The present 150 years has seen an average of about 2 mm/y with a bit over 3 mm/y in the 1990’s but is now down to less than 2 mm/y the last few years. Even at 3 mm/y, this is only 1 foot per century, and I don’t think that threatens Sacramento Valley of CA in the forseable future.

Over the PREVIOUS century, sea levels have risen by about 20 cm or about 8 inches. The important question here is how much will they rise in the current century. Note that most of the warming of the previous century occurred during its most recent decades and that the rate of sea level rise is now increasing (the red curve shown are measurements taken by far more accurate modern satellite-based methods and these are indicating faster rates of sea level change). Many experts in this specific field of sea level measurements think that sea levels by 2100 will be AT LEAST one meter higher.

The only two reasons I can think of as to why one might not worry so much about future sea levels at Sacramento CA are: (1) you don’t live there or (2) you are assuming that AGW will occur only at the rate of the previous century.

Tom Curtis @246, in 161 you dismissed Tom Vonk’s arguments on the basis of your own speculations. I don’t care which data did you use, your own source or his, but you OWN corollary was:

“The change in forcing due to a 10% increase in cloud cover is therefore, unlikely to excede 1.5w/m^2 globally averaged, half that of the estimated increase in CO2 levels”

In 165 I have shown that a reputable model (as presented by an institution of AGW stronghold and therefore must be trusted by you) disagrees with your assessment by about TWO ORDERS OF MAGNITUDE. I would not defend exact accuracy of this model, whether 1.2% or 1.6% of low cloud cover makes it equal to CO2 doubling or argue about other 10-20% deviations, but I am confident that the model captures the effect to the order of magnitude correctly (otherwise it would be a big embarrassment to the official academic position).

Therefore, when someone points to your error of TWO ORDERS of magnitude big, what is foolish is not to respond as quick as possible. Instead of your lengthy diatribe of long chain of shonky reasoning @246, a simple conceding would suffice.

Tom Curtis @247 wrote:
“you completely fail to account for what portion of the CO2 is removed from the area by wind, ie, simply removed to another portion of the atmosphere.”

I don’t think I did. If you examine the data sources I used to estimate daily fluxes(1 @ 28), these are not the waves of some blobs of accidental CO2 excesses all carried by local wind, they are day-night influxes and outfluxes across the entire layer, regardless of wind or no wind.

There is also no need to blame me for under-representation of temperature or concentration fields as a single number; you probably should be aware of my position on the most “important AGW tool” as “global average temperature”. In this particular case I am using the same level of abstraction as when NASA divides 750GT of atmosphere by 200GT per YEAR of global sinks, and arrives at 3 years of “removal time”. Apples to apples. My point simply was that there are diurnal processes that move much more CO2 than the common annual average suggests. You are still missing the point that there are actual physical processes that acts on local ABSOLUTE concentrations of CO2, while the bulk sees only “leftovers” from these processes. The Keeling curve might be a good bookkeeping tool to account for these leftovers, but tells nothing about actual turnover rate and mass of CO2.

@266 Eric, I plan to follow up in this discussion where we left off way back in my @158. I have been reviewing our discussions after @158 to see whether there is any reason to deviate from simply beginning with @158 all over again. I may simply proceed by following up on my point #8 of @158.

Meanwhile, I just created another sidebar that may be a better place to discuss sea-level changes. I named it “S. Sea Level Change” and entered some short summary articles from CO2 Science which I believe represents the best available summaries on this subject.

With these summaries as a reference, I invite you and anyone else to continue discussions of sea level, especially by relating your comments to the CO2 Science summaries. This provides reference points that I think are missing in some of the above comments on sea level. Henceforth, we should not do any more discussion of sea level in this post #6.

Tom Curtis @270, thanks for demonstrating that the model presented to public on website of Prof. D. Archer, a devoted proponent of AGW and founder of RC, is close to be bogus. I am not sure about mathematics involved therein, but the default set of parameters appears to be not right. A man with your globally-averaged IQ should know something about water content of clouds, and should be able to figure out in no time that their default water content is exactly three orders of magnitude bigger than it could be in reality. That’s why your 10% gives an absurd result. I am sure that they (AGW modelers) do not have a similar vapor adjustment mistake. With your help we have established here a new level of trust in climate models, thanks. Lesson learned, I stand corrected, the model sucks, and I should not be using it as an argument.

So, I guess we need to settle on empirical base. I am not sure which data are you using, but I am aware of Earthshine experiment that has detected a long-term drift in albedo from 0.319 in 1985 to 0.297 in 1999, a 2.2% change. This albedo drift is corroborated by reconstructions from ISCCP cloud database, which shows a 10% anomaly in cloud cover over the same one and half decade, or 3% global change. This 2.2% albedo change makes direct “forcing” of about 7.7W/m2, which is an equivalent of CO2 quadrupling. So, as we can see from undisputed hard data, natural and yet unexplained variations in albedo are 5X stronger than entire alleged forcing form CO2 emitted since the beginning of industrial revolution. Therefore, your estimate is still an order of magnitude off.

For those seeking context, post 165 was a responce to my 161, which was in turn a responce Tom Vonk’s 143. The primary basis of my criticism was that Tom Vonk compared changes in temperature with total temperature inputs to incorrectly indicate the comparative size of the effect. In doing so, I merely used TomVonk’s cited source of data. Therefore, in as much as there is a problem with that data, it is his, not mine. Even if the data is suspect, my logical analysis of TomVonk’s shonky reasoning still stands. (Point 1)

You misunderstood and misinterpreted about everything.
The point being that if you ignore the cloudiness , you ignore radiative fluxes and if you ignore radiative fluxes , you ignore temperature dynamics .
Your “logics” consists to claim “I know little but I will arrogantly yell that I know everything. The decibels thrown at “shonky” reasonings will hopefully make an impression.”

Well they don’t.
The paper I linked was just destined for your general education as an example, it can’t of course be used in such a naive way like you did.
Like Al has correctly shown , 1% of cloudiness variation is enough to cancel the weak CO2 signal. This is just again an example for your education.

It may be more or less according to additional hypothesis one takes.
But it definitely matters and it is the greatest factor impacting radiative fluxes.

You don’t need to write kilometer long rants that are largely irrelevant to the point.
One phrase would be enough :
Yes , cloudiness is the major factor influencing radiative fluxes and no we have no clue what it was 100 000 years ago let alone 40 My. And yes the knowledge of the radiative fluxes is necessary to distinguish the different GHG impacts.

Tom Curtis @274 an @275, I understand your efforts in finding various arguments for CO2 case. Unfortunately, all your estimations are still one-sided and biased. You do realize that arguing about “CO2 radiative forcing” and its (alledged) value of 3.7W/m2 is like arguing about the number of angels on a pin tip.

For example, you mention “trapped LW radiation”, and apparently you mean some increase in ‘backradiation” from clouds. Unfortunately you failed to consider that cloud cover is not a constant, it has a substantial diurnal cycle, see for example:

ams.confex.com/ams/pdfpapers/108110.pdf

“The highest values of cloud cover were usually found just after solar noon”.
Spot checks show that the average variation is from 60% at night to 85% at daytime.

Form common experience, every child (and solar radiometer) knows that clouds block sunlight down to 10% and below of peak insolation, which creates “forcing” variations of the order of 200W/m2 (if spread over 24 hours). Yet the simple IR thermometer test would indicate that temperature difference between clear and cloudy sky is about 10C, which roughly translates into radiative flux difference of maybe 30W/m2, or an order of magnitude smaller (on daily average). Everyone knows that cloudy weather is generally colder that sunny weather.
Therefore, all your arguments about fine “forcings” of 2.2W/m2, 5.3W, or other equally miserable numbers are inconsequential. You probably need to correct your math regarding cloud effects, and do not repeat the typical mistake of climatology of using averages without discretion.

1. That I forgot to include sea level change.
I didn’t forget to include it. It’s irrelevant to the argument because there’s nothing we can do to change sea levels in the first place because temperatures & sea levels are controlled by a complex climate system that’s controlled primarily by constantly changing cycles of solar activity. All of the various models and predictions that you alarmists have come up with so far have been shown to be wrong. So why should I concern myself with anything that the advocates of AGW says at all? And since we can’t control our temperatures, the entire issue is in fact an irrelevant farce which merely serves to waste our time and our financial resources, while helping the Socialists / Marxists take away more and more of our liberties.

2. What coincidental occurrence is responsible for the other 85 ppm of CO2?
Rising temperatures of course… As temperatures have continued to rise over the last 150 years or so (which is what’s supposed to happen as we come out of the Little Ice Age) and may continue to rise, (even though we’ve been in a cooling trend since 1998), more and more CO2 comes out of the oceans, and from other natural sources such as rotting vegetation. Even if our CO2 levels have risen above the highest levels that they’ve been for thousands of years, it’s not logical to simply assume that it’s our fault or that there’s anything to be concerned with. The top scientists in the field, (people like Dr. Lindzen) have already demonstrated that no matter what happens to CO2 levels, they can’t have any serious impact on climate change. This is the 3rd or 4th round of climate hysteria in the last hundred years. 35 years ago, your crowd was in a panic over the coming ice age. I suspect you’ll be back to that absurd story in about 25 years. Since all of the others proved to be false alarms, why would any rational person listen to these climate alarmists now. Climate change moves slowly, It happens over hundreds of thousands & millions of years. Nothing that happens over any specific 25, 50 or 100 year period has any significant long term meaning at all.

3. The threat that CO2 poses to the food basket.
You base your claim on the incorrect assumption that the sea levels are going to rise to a sufficient level to flood the Sacramento Valley. But even if they did, if the CO2 levels keep rising further, more and more land that’s been marginally useful or useless to farmers till now, would become usable in more than sufficient amounts to compensate for any farmland that might be lost. So we’ll have an enormous lake in California… Why worry about that since there’s nothing we can do to prevent even if it happens, in a couple of centuries after we’re dead and forgotten.

4. So what then is the most abundance GHG that is a permanent component of the atmosphere?
Water vapor of course. Your implication that it’s not permanent is nonsense. Its effect as a greenhouse gas is probably 15 to 18 times greater than the of all total CO2 (let alone the paltry amount that we produce). The amount of it in the atmosphere surely varies, but it’s never been zero and it never will be in the future based on what’s happened in the last couple of billion years.

5. That my comment “The following is usually sufficient to explain the issue to most people” was not a very nice thing to say about people – even if you are correct!
So what if it was? I couldn’t care less about people who can’t understand that simple graph, and since I view the entire AGW community as a bunch of fools, liars & con men who pose a serious risk to the world I live in, I don’t care a bit if they’re offended by what I said. The last thing that anyone on the “right” side of this debate should do, is act like the hypocritical liars in congress, who refer to their arch enemies in their chamber as “my good friend and colleague”. You might be the nicest guy in the world, and I’m sure that you are if Ed asked you to play a part in this little drama, but while that might extend to my enjoyment of your company on the golf course or on a fishing trip, there’s no way I could ever respect you knowing your position on this issue. This isn’t a debate over something inconsequential, like whether sailboats are more enjoyable than motor boats. This debate is about something that poses a life or death threat to most of mankind. Familiarize yourself with the truth about Agenda 21, and you’ll understand why I feel this way.

6. Where you could get some of that easy grant money sloshing about?
If I and people who think like I do, can manage to tar & feather the progressives and kick them the hell out of town as they deserve, that gravy train will disappear in an instant. So hopefully you’ll have another way to feed yourself, as long as it doesn’t involve you teaching this bogus science to the younger generation.

Tom Curtis à 272TomVonk @272, yes, the fact that you consider me an idiot is indeed a pleasant thing for me.

You misunderstood as expected but it begins to be a habit with you .
What I said was something completely different .

Back to the clouds . And I will just give some back of the envelope estimations because obviously you are not able to follow the more detailed comments of Al .

Most of the incoming energy concerns the equatorial part of the day half of the Earth and it is also there that the albedo effect is strongest .
Let’s take the 30N-30S band .
The irradiated part of this band represents 1/4 of the Earth surface .
Let’s take the cloudiness at 1/3 just to fix the ideas .
Let’s also take the difference between covered and clear area within the band at 200 W/m² (a conservative order of magnitude) .
Now let’s suppose that the daily cloudiness in the Equatorial band increases by 10 % .
The overal cloudiness will increase by a small 2,5 % .
But the overall incoming flux will be reduced by 1,3 W/m² what is the same order of magnitude we talk about for CO2 doubling .

Is it understood now ? A very small variation of the cloudiness changes the incoming flux by values equivalent to what are supposed to do very large variations of CO2 concentrations .
And you want to neglect that ? Well be my guest but don’t expect that somebody will believe one word you say .

People,
This section is titled “The-Last-Major-Ice-Age”. If we keep the discussions on topic in each section, it is easier to go back and forth, and keeps the number of comments more reasonable. You need to be in a section on clouds, or greenhouse gas forcing, or something else for a lot of these comments.

Dr Eric (I forget which number),
You made a comment earlier that large sea level and ice thicknesses changed during glacial periods with only very small CO2 changes, therefore CO2 is even a bigger effect than we think. I only see that CO2 is not shown to be any cause for these, and it tracks only due to ocean outgasing with warming. Your presupposition of cause and effect is without any reasonable support.

“My figures, are of course from Ramanathan et al (1988), reporting on the Earth Radiation Balance Experiment.http://www.sciencemag.org/cgi/content/abstract/243/4887/57
It appears to me that the reason you consistently reject the emperical data is that, while it shows clouds to have a significant effect on global climate, it does not show them to have a dominating effect. “

Are you sure we a reading the same article, or your Aussie-English is much worse in reading scientific English than my heavy Russian-Texan accent?

I read the following:

“The shortwave and longwave components of cloud forcing are about ten times as large as those for a CO2 doubling. Hence, small changes in the cloud-radiative forcing fields can play a significant role as a climate feedback mechanism.”

Which part of “ten times” you do not understand? Or you will be arguing that ten times is “not dominating”?

@ 293, Tom Curtis,
While different amounts of back radiation occur under clouds, the only real effect on average global warming is due to the effective albedo (incoming absorbed energy) and the effective altitude of outgoing radiation. Since except for the atmospheric window, most of the outgoing radiation leaves from above the cloud layer, and the adiabatic lapse rate is (on the average) not affected by radiation level, then by far the main long term effect of clouds would be the albedo, which is a cooling. Back radiation alone does not heat on the average as long as convection maintains the lapse rate. It can cause transient effects (clouds at night can trap energy from clear heated days, but clouds day and night are cooling).

Tom Curtis @299, you continue to throw some numbers from old articles without realizing that they are not “hard data” but results of sophisticated processing. Practical impacts of their definitions of “cloud forcing” can be disputed.

You are obviously trying to downplay the importance of cloud variations, and wrote:

“… an effect so large that global temperatures in geological times are unlikely to be correlated with ghg concentrations.”

Why it would affect the correlation? It was explained to you that the correlation between ghg concentrations and temperatures has a simple explanation – warm oceans outgas more CO2, and cold oceans dissolve more CO2, that’s enough for the correlation and also explains the lag. Whichever drives temperatures drives CO2, very simple.

The fact is that climatology has little idea how to have clouds as prognostic variables in models. But let me save you an effort and present the final thoughts on this matter from the scientist who instrumented all these papers that you like, V. Ramanathan. See his article on P.18:

www-ramanathan.ucsd.edu/files/brt22.pdf

“Why is Earth’s albedo 29% and was it always 29%?”

“A global albedo of 32% would plunge the Earth into a climate similar to that of the last ice-age; while an albedo of 27% would be comparable to a seven-fold increase in the CO2 concentration, close to the values required to bring the planet to the warm cretaceous. Given this state of the field, and given the fact that clouds exert a large global cooling effect (about –15 to –20 W m–2 globally), scientists need to understand the processes that constrain the Earth’s albedo to be around 29%.”

“Most if not all geological and geochemical studies on the evolution of the Earth’s climate have implicitly or explicitly assumed the albedo to be 29%. While some have accounted for ice sheet and land surface variations on the albedo, the clouds have implicitly been assumed to be the same as today. Is there any justification for this assumption?”

“There is one hypothesis, however, which proposes albedo-climate feedback as a regulator of the planetary climate. The GAIA hypothesis [1] invokes black daisies (greenhouse gases) and white daisies (clouds and aerosols [2])”

And the final thought of the article:

“The GAIA hypothesis has remained untestable [7]. We need a more testable hypothesis that not only addresses the questions raised here but also explains the albedo puzzles posed in this paper.”

Translation: despite the undisputed fact of substantial impact of clouds, climatology knows nearly nothing what controls the cloud cover and therefore the climate. The reference to metaphysics of “Gaia” is remarkable.

Conclusion: All speculations of Dr. Eric regarding influence of CO2 on climate cannot be supported by presented correlations from ice cores.

@ 302, Tom Curtis,
All of the speculation of what drove temperature variation in longer distant geologic times is without any solid support. Super volcanoes likely added large amounts of CO2 at times, and not always with increasing temperature. Plate movement affected ocean currents. Different cloud level, variation in the Solar intensity, and possible variations in Earth tilt may have varied enough. Different types of sea life forms may have rapidly absorbed or released quantities of CO2. The best overall data has a poor correlation between CO2 and temperature.

In the much more recent times (last 800,000 years) Earth has been basically in a glacial period, with short jags into interglacial periods. The most likely trigger cause of the jags is variation in planetary tip. We simply do not know if there were other feed backs. Clearly temperature variation was a major cause of CO2 concentration up to recent times, but the possible nonlinear effect of sea biota makes the straight chemical vapor pressure effect not necessarily valid. It is also quite clear that long period ocean currents can have large effects on temperature. The main point I am making is that we do not know all of the causes and effects. Even within the Holocene, D-O and other cycles show large and fast temperature variation not caused by humans. The present small variation is nothing unusual with the possible exception that humans caused the CO2 level to increase more than recent natural causes did. Since the temperature variation is so far not especially significant compared to other variations, there is no valid support that there is a positive feedback or that we are heading for problems.

Even the precautionary principal is not applicable here. There is a significant chance we are approaching the end of the Holocene, and heading for cooling, which would be far worse than a small amount of heating. In that case, trying to prevent heating may trigger the early cooling. For this case, we need to know more before we do anything.

@ 302 Tom Curtis,
Keep in mind that oceans cover over 70 % of the Earth. In fact, there are lakes and rivers that add water area over some of the land. Thus the albedo of Earth surface is dominated by water and this absorbs most of the the sunlight and does so uniformly. Cloud variation over water is therefore a major cause of change in albedo, and is the main location for clouds due to this area. Using desert and forest as compensating is not a major factor.

@ 305 Tom Curtis,
Look at http://www.geocraft.com/WVFossils/Carboniferous_climate.html
This seems to show only limited correlation between CO2 and Temperature. Since CO2 was far higher than present most of the time (we are in an unusually low period), and the temperature cycled up and down in a limit cycle between 12 C and 22 C, there are also basic limiters. However, it appears the presence of large land mass at the S. Pole and Greenland near the N. Pole, along with the location of the connection between N. & S, America are major factors for the long present ice age. The increased solubility of CO2 (and O2) in sea water with cooling, and the higher biological activity in cooler sea water (due to the CO2 and O2) remove and sequester CO2. Just saying the CO2 causes the high temperature is without any real support.

Tom Curtis @302
(1) I am tired of your groundless rhetoric. I don’t reject data; I question statistical interpretation of post-processed, selectively averaged and re-analyzed data. Climatology is full of examples when initial instrumental data are “re-analyzed” and alleged “errors” are “corrected” in order to fit into preconceived concept of global warming. ARGO floats is one example.

(2) You continue to misrepresent my arguments and change the topic. My argument about CO2T relationship was about natural cycles in past glaciations within ice core record timeframe. You continue to interject numbers from man-made time frame or from very distant geological past. And you continue to use arguments like “…increase of 11.76 ppm CO2 will result in an increase in temperature of just 0.17 degrees C”. This relationship is exactly under questioning here, and using it in your arguments is circular reasoning, nonsense. Once again, the best explanation of all discrepancies in CO2 behavior is that T does not depend on cO2 in any significant degree. In some epochs of relative equilibrium (as the last 800,000 years) the CO2 follows solubility equation, in some epochs the CO2 was in excess, but temperatures (as we know them from proxies) were never out of life-sustaining bounds.

(3) Once again you continue to misrepresent my line of arguments. Every time I mention the modulation of insolation by clouds, I also reflex on increased backradiation. Therefore please retract your half-understanding that I am using “albedo alone”. In fact, I was not using any albedo arguments at all.

Apparently you do not understand that there are several ways to consider energy balance in planet’s atmosphere. You keep referring to the balance at radiative TOA, while I am impressed with variations at the other boundary of the climate “heat pipe”, at the surface, and always account for contribution of clouds to backradiation. Due to conservation of energy across atmosphere, these two approaches must be equivalent. Unfortunately there is about 10-fold difference in the variance, which needs explanations.

Your obsession with numbers and their presentation with unfounded accuracy is ridiculous. Look at the original:

www-ramanathan.ucsd.edu/files/pr53.pdf

It says that “net forcing” was from 13.8 to 21.1W/m2 from year to year, and uncertainties from “identification errors”, “incorrect categorization”, “sampling errors”, and “statistical assumptions” may result in 6W/m2 OVERESTIMATION in clear-sky LW radiation, such that the “cloud forcing” could be 20 to 27W/m2/ Another cited analysis determined that r.m.s. “uncertainties” in pixels are 42W/m2 (!!!), and they use some untested speculative assumption that “1/5 of pixels are independent” to shrink this horrible error bar to 2W/m2. In short, the whole data are too fishy and noisy to derive any believable conclusion and any reasonable scientific confidence.

(4) You say, “Finally, you missed the fact that the article clearly hints at one way that albedo could remain constant despite large variations in cloud cover.”

No, I didn’t miss the hint that “albedo could”, I ignored it. I ignored it because it is not true; we know from Earthshine observations that albedo can vary by 10% over one and half decade timeframe.

Leonard @306, I have previously commented on the Scotese temperature reconstruction. Briefly, it is made by comparing the spatial distribution of various vegetation and animal fossils, and rock types to determine past temperatures. The indices are classifies as being tropical, temperate or arctic deposits, meaning the temperature range of deposits is sorted into three very broad categories. This is the reason the temperature index tends to switch between 10 and 25 degrees C, with only short intervals (and few) at other temperatures. It is also why you have extended periods, in one case over 90 million years, plateaud at a constant temperatures. These facts show the temperature “reconstruction” to be very inexact.

Further, the time periods are broken up into parts of geological ages. For example, the entire Silurian (25 million years) is treated as a single time interval with no internal discrimination. This yields a very coarse time discrimination of the reconstruction, with a temporal discrimination rarely better than 15 million years. So while in some senses indicative, Scotese’s temperature reconstruction has no where near sufficient resolution of temperature or temporal interval to test hypotheses about CO2/ temperature correlations. Further, later reconstructions using a better methodology have clearly shown significant errors in the reconstruction with regard to temperature. In this respect, it is worthwile comparing Scotese’s temperature reconstruction of the Tertiary era with that shown by Dr Eric near the start of his post. Or indeed, with the article to which I linked in 305.http://www.scotese.com/climate.htm

Tom Curtis @309 wrote
“I loved this so much I had to quote it.
“Every time I mention the modulation of insolation by clouds, I also reflex on increased backradiation. Therefore please retract your half-understanding that I am using “albedo alone”. In fact, I was not using any albedo arguments at all.”

If you do not see the simple contradiction in the highlighted sentences, please (oh, so very please) explain to me how clouds modulate insolation without changes of albedo. Because SFAIK the only way clouds modulate incoming sunlight is by reflecting it.”

There is no contradiction Tom.

First, if clouds do change the albedo, it doesn’t mean that one has to use the albedo as an argument. See the flaw in your logic?

Second, it seems like a surprise for you that the cloud system is a layer, and as such it has two “effective” boundaries. Whichever item is reflected from the top is not necessarily “equivalent” to what irradiates down from the bottom.

Third, you seem to fail to notice my remark that I am considering the ground surface. According to overall energy budget as estimated by Kiehl and Trenberth (and common sense), the only AVERAGE INPUT to surface is the insolation (or what remains of it), and the IR radiation difference (between surface OLR and backradiation). The other components you mentioned (latent heat, convection) are for OUTGOING flux, about which I am not concerned at this time.

Forth, your musings about “correlate” versus “equivalent” indicate that you don’t understand implications of conservation of energy. The surface energy budget is precisely EQUIVALENT to energy budget that crosses your virtual TOA line, period. However, “equivalent budget” does not mean “identical itemization”, and fluctuations of limited time averages of items may differ qualitatively and quantitatively at both surfaces. Obviously I don’t expect you to understand this statement.

Finally, the cloud layer not only reflects incoming radiation, it also absorbs substantial part of 78W/m2 of incoming radiation, on average, again according to K&T budget. Obviously, cloud cover also modulates this part of spectrum as well.

So, the laugh is all mine, dear Tom Curtis, you have less than “half-understanding” on all counts. I just don’t understand, why you are so jumpy? Your resistance is futile. Please don’t write self-incriminating musings any more.

Tom Curtis @313, these are still incorrect figures, your “341” and “494”. As I said, the concept of “budget” appears to be foreign to you. As Dictionary.com says, it is “an estimate, often itemized, of expected income and expense for a given period”. Therefore, the correct budget at these two atmospheric boundaries is “approximately zero” and “approximately zero”. But you always can look at fluctuations of individual “items” in the budget, but it better be in the same budget and not the one in the sky (or vice verse).

You also conveniently forgot to acknowledge your blunder when you tried to ridicule me with a statement, “Because SFAIK the only way clouds modulate incoming sunlight is by reflecting it.”

And @314, just for completeness of your image as determined AGW supporter who claims knowledge of “true connection” and preach about accuracy of climate science.

You said: “These figures are, of course, very crude approximations.” Yet this revelation (of truth BTW) doesn’t prevent you from quoting numbers such as “254.4”, which implies precision better than 0.4%. Every schoolchild would recognize this as nonsense. You’ve been curious why I picked on your “11.76 ppm increase”: for the same reason. Unfortunately, this kind of misleading overconfidence and failure of error propagation analysis is typical not only for AGW propagandists and enthusiast as John Cook, Coby Beck and other climatards, but for a certain entire layer of “official” climatology.

You continue: “I wished to point out that even using the study he quoted regarding changes in Earth’s albedo at face value, it clearly indicates a very strong cloud LW forcing, countering the effect of the albedo.”

I am really curious how could you say this with a straight face, when even the best rounded and averaged estimations of both counteracting forces show the net effect of clouds as being equivalent to 7-fold increase in CO2, as one of stalwarts of AGW climatology explicitly formulated himself?

My concern here is that with “experts” like Tom Curtis and chief Prosecutor, we have very little chance to progress to any understanding why the AGW theory of CO2 dominance, being so nice at the surface, fails to explain reality. Especially if they will keep withdrawing and hiding from intellectual confrontation.

@ 308, Tom Curtis,
The first point on the reference by Royar was the claim in the introduction that it is known that CO2 causes heating, and is responsible for most of the recent temperature rise. It is starting with circular reasoning and an agenda. Second, the location of land near the poles and in effecting ocean circulation patterns is likely important to glacier and polar ice formation. This is not considered as important in the paper. Third, I need to know where the increasing CO2 came from that drove the heating. If it was volcanic, then other volcanic effects (aerosols, and other gases) may be the critical ones, not CO2. Fourth, biological processes may have been the drivers, and increased CO2 was then indirectly responsible as the source of biological super activity. This is not a greenhouse effect. Again, it is not clear if CO2 drove temperature, or temperature drove CO2 increase. Keep in mind that oceans have about 50 times the Carbon as atmosphere, and ground has many thousands as much. There are many more possibilities, but I will end with the comment that the probable accuracy of global results from the material are limited.

Even with all of my comments, the paper is one that can be included in the indicators, and may be found to be a strong supporter of AGW. I do not reject it, just treat it with proper skepticism, as it should be treated.

@ 318, Tom,
Comments on the paper by Royer
In the abstract:
“A pervasive, tight correlation between CO2 and temperature is found both at coarse (10 my timescales) and fine resolutions up to the temporal limits of the data set (million-year timescales), indicating that CO2, operating in combination with many other factors such as solar luminosity and paleogeography, has imparted strong control over global temperatures for much of the Phanerozoic.”

In the introduction:
“Carbon dioxide (CO2) is an important greenhouse gas, and its role in regulating global surface temperatures has been recognized for over a century (Arrhenius, 1896; Chamberlin, 1899). It is now generally accepted that the 36% rise in atmospheric CO2 since 1860 (280–380 ppm) is partly responsible for the concomitant rise in global surface temperatures”

While the abstract seems to fairly show possible multiple causes, the introduction seems to accept the CO2 is very significant, and possibly dominate. That is OK, as far as that goes, however, the paper then concentrates trying to prove the dominance. It does not attempt to find the other possible causes. All of the curves in fact only look at CO2, and in fact DO NOT have any temperature data at all, only indicated cold periods at some locations and glacier periods for some selected locations. Not as strongly circular as I seemed to indicate, and I withdraw that it was strongly biased. I would call it weakly biased, and essentially a one sided view in the body of the paper. If the results were clearly supporting the CO2 cause, I could even go along with the paper. However look at the next examples.

Some text:
“The longest and most extensive Phanerozoic glaciation occurred during the Carboniferous and Permian, during which time Antarctica and Australia drifted across the South Pole (Frakes et al., 1992; Eyles, 1993; Crowell, 1999). Traditionally, this glaciation is considered to have lasted from the base of the Namurian to the top of the Kazanian (326–267 Ma; e.g., Frakes et al., 1992), some 60 my in length. Broadly speaking, this cold interval corresponds with low levels of atmospheric CO2”

This text would indicate to me that large land areas over the Polar Regions are likely needed to cause major glacier formation leading to albedo increase. Cooler water temperatures would then absorb CO2 and reduce the atmospheric CO2 level. The cooling leads the CO2 drop. Coincidence? The present few million years are also periods of land on or near the poles, and large glaciers and low CO2. Coincidence?

More text:
“However, there is a distinct period of elevated CO2 (1500 ppm) centered at 300 Ma (Fig. 3A); based on the traditional age placement of the Permo-Carboniferous glaciations, this period of high CO2 weakens claims for CO2-temperature coupling across the event.”

That text is self-explanatory.

I think the paper does a basically fair job of presenting what is known accurately (but what is known is sadly limited), it is the emphasis and lack of any convincing indications that CO2 is the driver. I would have accepted the paper with only small changes in emphasis if I were a peer reviewer for it, but would conclude when trying to use it as evidence supporting CO2 as a major driver of temperature that it was at best a neutral paper, not supporting or rejecting.

Look at Fig.1 that shows overall distribution of used proxies. The most striking place would be two proxies at about 200My.

(1) Panel “B” shows two data points at 6000 ppm with error bar of about +-1500 ppm, or a possibility of up to 7500 ppm in CO2.

(2) The next panel “C” shows the same data as compared to some model called “GEOCARB-III” shown as a shadow. Notice something? Yes! All error bars disappeared! The data therefore are now a much better fit into their model.

(3) Now, the panel “D”. Wow, if you smooth the proxy data, the fit gets even better, almost perfect! Viola, science has spoken, theory has been validated by observational evidence!

Wait a minute. The observational data shown in panel “B” came with error estimate. Unless you dispute the original research data and their error analysis, there is NO WAY that CO2 concentration was below 4500 ppm at that time. The error bars indicate this with nearly absolute confidence. There were also several data points above 4200 ppm and 3000 ppm. Yet the wonders of statistical averaging (“weighted regression”) of apples with oranges reduced the “observed” CO2 concentrations to a smooth curve that lie entirely below 2000 ppm at 200My bp. What kind of science it is? Garbage. No matter how do you later speculate about “fidelity of proxy record”, “vast majority of proxy data fall within uncertainty envelope”, this is all unsubstantiated GARBAGE. Tom Curtis can call it “emperical (sic) research”, I call it pathetic junk science. Period.

[BTW, I have few more examples of this climatological practice of “gradual inflation of confidence”. One example about “CO2 forcing of 3.7W/m2” was recently discussed in “G” thread.]

@ 318
Regarding your comment:
“The most efficient way that the biosphere can effect temperatures is by changing albedo by grasses growing over deserts, and forests growing over grasses (or vice versa). In this case, reduced albedo”
You then follow by saying this also reduces CO2. However, the CO2 level is due to the balance between volcanic source and sequestration. Ocean sequestration is far the main cause. However, as temperature increases (from whatever source), the oceans tend to release more CO2. Thus warming may result in net CO2 increase as well as more reduction in albedo, and the albedo effect may dominate, and thus biological positive feedback.

@ 318,
I want to discuss your point:
“Clearly CO2 concentrations throughout the phanerozoic have not been a response to temperature ranges.”
This is based on the more recent level change of CO2 with temperature from ice core data (about 12 ppm per degree C). This increase in the ice cores is probably due to out gassing of the oceans causing CO2 increase whenever the temperature increases, and your assumption that this is CO2 then causing the main part of the temperature change with positive feedback included. The closest you come to supporting this is the much higher CO2 levels in the phanerozoic were too high to be explained by this small 12 ppm per C.

The first thing you have to keep in mind is that the presence of large glaciers seems to uniquely be dependent on the presence of large land areas near or at the poles. The only two periods of low CO2 are associated with relative cool periods and land at the high latitudes, and large glaciers. This is not a volcanic CO2 production effect, so CO2 is obviously not the driver here. Next, the lower ocean temperature is set by a thermohaline like circulation for at least the present. Water pushed to the polar regions cools and goes to the bottom. This type current depends on land location. If the land masses are located such that they inhibit these circulations, the deep water would depend more on the location where it circulates. It is likely that as plates drifted over geological times, the depths were much warmer than at present. Since the CO2 solubility is strongly temperature dependent on temperature, and since the oceans have (at present) about 50 times as much dissolved Carbon as the present atmosphere, it is quite reasonable that rather than 12 ppm per C, that 10 time this amount (120 ppm per C) could be released from the oceans at these conditions. This is still only 20 % of the amount in the oceans. Thus a concentration of 3000 ppm could be associated with only a 10 C increase, and the temperature, not CO2 be the driver.

The question arises, why is the temperature increased. The land location at the poles or lack of land, changes the presence of glaciers, and thus changes albedo. Also we do not know if the solar activity is that stable over long geological periods. It would not take much to perturb a change of a few degrees.

Leonard Weinstein @321, I agree that the main drivers of CO2 concentration are vulcanism and ocean sequestration, ie, the chemical absorption of CO2 in material that then falls to the ocean floor as sediment, not to be confused with the simple dissolving of CO2 into the ocean. However, one of the largest reductions in CO2 was that durring the carboniferous, which resulted from the growth for the first time of trees, and the consequent formation of coal beds. Further, around 20% of human CO2 emmissions come from changes of land use. It follows that large scale changes in vegetation, particularly the formation or destruction of forests can have a significant (though not dominating except in the short term) effect on CO2 levels.

@ 318
There are periods of glaciers with little or no land at the polar regions, but they are supported with very little data, are relative short lasting, and may have been caused by solar variation, or ocean currents suitable for deep ocean cooling caused by non polar land location (while glaciers likely dominate the albedo change, it is the deep ocean temperature that probably dominates the CO2 level). The example of near polar land without glaciation is also weakly supported, but even if true, again may have been dominated by land location controlling ocean currents and preventing deep ocean cooling. The only long and best supported cool periods are clearly associated with high latitude land, and likely had suitable ocean circulation patterns.

@ 324,
Tom, I agree that human activity can and did change recent CO2 levels, and that biological activity can dominate CO2 removal under certain conditions. The point is that it doesn’t always have to go that way (deep water temperature change may dominate under some conditions). Also, we are discussing if the CO2 level is driving the temperature level, or the temperature driving the CO2. There is obviously some of both, and the need is to find how much of each. After careful re reading of Royer, I agreed that I thought it basically did what it said it would, and was basically fair, but that my conclusion was that it did not support it’s basic case well enough to be convincing that CO2 was the dominate cause of the major temperature variations. CO2 is a greenhouse gas and does affect temperature. I just have not seen any convincing evidence that there is positive feedback.

@ 324
The Carbon that is dissolved in the ocean is not sequestered. Dropping shells, coral, and even dead plants dropping to the sea floor are sequestered. The 50 times quantity atmospheric Carbon in the sea went in as CO2, but chemically reacted with sea water, so that only part of it is dissolved CO2. However, these are reversible chemical processes, and removing CO2 by warming the water causes some of the other forms to replenish the dissolved CO2 fraction, so that most of the total dissolved Carbon can be released as CO2 gas over long periods. Thus there is no difficulty getting several thousand ppm atmospheric CO2 out of the oceans if the deeper water warms several degrees.

Thus: P/Po=2 to the power (ΔT/16)
where the P’s are partial pressures of CO2.

Now the temperature change from glacial to interglacial periods in the last several hundred thousand years varied somewhat, but a typical change of 10 C occurred at the transition up. This would cause an increase in CO2 partial pressure (in the ocean) using the above equation of 1.54 times. That is, the CO2 partial pressures would go from 190 ppm to 290 ppm. Do these numbers seem familiar? The argument was made that the small temperature change due to Milankovitch Cycles then caused the release of some CO2 after a delay, and this then boosted the final temperature. However, the amount of CO2 increase is exactly corresponding to what would be expected to heating the surface seawater by the indicated actual temperature increase.

Since there is so much dissolved Carbon available (50 times as much in the oceans as in the atmosphere), why would the process stop here? How would more externally produced Carbon from long term super volcanoes or from human burning of fossil fuels change this. It appears there is no reason for the process to stop where it did, if feedback is there and still available at higher Carbon levels. This would appear to imply that a positive feedback would have to be a runaway feedback as long as excess Carbon is available in the oceans or that there is not a positive feedback at all (but there can be a negative feedback).

CO2 clearly is an atmospheric greenhouse gas. If long-term excessive volcanic action or a reduction in CO2 sinks (probably sea based plankton or land biota, or exposed rock to absorb CO2) lets the CO2 drift up to a much higher level before a new equilibrium is established, the CO2 would raise the temperature some. For example if the CO2 were at 3,000 ppm (8 times the present concentration, or 3 doubles), and if the sensitivity were 0.6 C to 0.8 C per doubling (reasonable values to me), the temperature would be higher by 1.8 C to 2.4 C than otherwise, and many glaciers could be at risk. This is not an unreasonable possibility. That is in reasonable agreement with geological data.

Note this assumed high level increase was not assumed to be due to a heating of the ocean and release of CO2 as occurred in the glacial/interglacial transition but an externally forced partial pressure increase which would lead to a new ocean concentration. The ocean converts excess dissolved CO2 to other forms of dissolved Carbon to reach a new equilibrium, and this is different from heating causing the release of CO2. The actual response over the last 150 years is clearly partially due to recovery from the LIA, and probably partially due to the CO2 increase with some negative feedback. The numbers work out very close to what has been actually observed for the assumption that half of the present rise is due to CO2. This means that going from the present CO2 level to a higher one due to human activity, the ocean will adjust, and the atmosphere may rise 0.6 C to 0.8 C per doubling if my analysis is correct. That means that if the CO2 reaches 560 ppm by 2100, the likely temperature (if all else were equal) would only increase by 0.3 C to 0.4 C above the present value.

@ 337, Tom,
First you say the temperature rise of 10 C (glacial to interglacial) was only at very high latitudes, not globally, now you say the very high latitude temperatures stay near freezing, i.e., do not warm. Which is it? Remember I am talking about the recent glacial to interglacial period. WHERE IS THE 10 C CHANGE HAPPENING?

The argument I made for long ago geological periods were not about ocean out gassing due to higher temperature, but a re balance of sources and sinks to result in a higher CO2 level. The ocean as a large source of dissolved Carbon was only used to show that any excess absorption or release is easily done with such a large excess. The place that is most important to determine atmospheric CO2 level is the high latitude surface oceans (not necessarily right near the poles), since that is the location where the water is most soluble to CO2 and where it would release it most easily at increased temperature.

@ 341,
I think even the models show that the largest temperature rises are not just at the poles but in the upper latitudes (I would expect that even without models). If that is so the water temperature where CO2 is mainly taken out of the air is high latitudes, and it is generally emitted at low latitudes. The total transfer is much larger than human activity per year. Thus if the absorbing region is 10 C lower and the low latitude emitting region 3 to 5 C lower in the glacial period, the 10 C probably still dominates due to the higher solubility, and this does give the correct level. At this point this is hand waving, but it seems reasonable.

@ 345,
As you point out, the location of cold water moves away from the highest latitudes to less high, this may increase the area of relatively cold water, and decrease the area of warmer water. This area change of the two extremes would strongly favor the cold water which has the highest CO2 solubility, and shift the level as stated. The bottom water would not prevent this.

By the way, where do you think the CO2 increase is coming from if not the water?

Tom,
When we consider millions rather than thousands or less year periods, it is almost certain that volcanic activity produces the excess CO2 faster than it can be sequestered until a new balance is reached. Land movement and type of biota are probably major causes of this, and also land movement affects glacier activity. Even my position on CO2/water vapor feedback allow that the temperature would warm some with much higher CO2 levels (about 0.8 C per doubling, or 3 C for 3,000 ppm). If the atmospheric concentration reaches several thousand ppm CO2, and does so for long periods, the oceans will not be emitting CO2, but absorbing if the temperature rise is small enough (the partial pressure increase far exceeds the solubility coefficient drop) . For this reason, we need to know the actual temperatures and ocean pH values to better determine what was going on.

Your position seems to be that at 3,000 ppm, the 4 doubling would give 2.8 C per doubling, and you also claim we have not yet seen all of the result of the recent CO2 rise. Altogether, your position seems to indicate that the temperature at 3,000 ppm should be about 13 C above present. However, the difference could be even more or less due to the solar intensity and albedo differences in the far past.

The result of all of the above is that we agree it likely was a bit warmer in the past much of the time, but we don’t know if that supports my position or yours. The general correlation is not supporting either position unless you have something more.

Only a dedicated AGW brainwashed “scientist” or outright green crook can imagine correlations in this kind of data. Sorry Tom Curtis, if you think that this is the kind of science that will made people minds, you are sadly mistaken. It is a joke.